(Boilerplate warning - this info is as of 2015-02-16 only, this info may be incomplete or incorrect, this may not work for you, or your environment)
For wheezy -> jessie users who do not want to manually compile packages AND keep systemd out of the system.
First, go to "options->preferences" menu on the aptitude and uncheck "Install recommended packages automatically" checkbox(or do equivalent on synaptic). This will also make your system more managable(stops installing unwanted packages).
Then HOLD OR DOWNGRADE POLICYKIT-1 PACKAGE TO 0.105-4 - this is the last version that don't depend on systemd related library. If you don't have this version, get this version manually from net and install it using dpkg.
I think all bad things starts from this package. - if you hold this(and be careful), you'll still be able to enjoy many of the improvements of jessie without installing most of the systemd crap(even systemd-shim). After this, there will be 2 problems left to your general desktop user experiences.
One is about login environment -> this relates to the fact that not long ago most of the display managers(gdm3,kdm,lightdm) became dependent on logind included in systemd(again corrected in kdm,lightdm so these 2 are safe again) - if you're paranoid, just use slim or wdm or xdm(since these 3 are ugly, you'll need some additional tweaking) instead and DON'T FSCKING USE GNOME3(gone are the days when one can install gtk/part of gnome2 libs only freely to use standalone(not gnome related) gtk2 programs. Gnome3 become more intermingled like windows) or XFCE4(core functions of xfce depends on libpam-systemd). If you are using LXDE, don't install lxde task since this depends on several packages which again depends on systemd. Install lxde-core task instead and invidual packages you want to use on LXDE(oh, and get/tweak pygtk-shutdown from net instead of existing shutdown button of LXDE to enable shutdown/reboot). Other simple WMs don't need to worry(just worry about DMs).
The other is printing. CUPS on jessie depends on colord which depends on libsystemd0 and policykit-1 so unless you use CUPS on wheezy version there is no simple way to prevent libsystemd0 from being installed on your system, but you can still prevent other systemd crap if you hold polcykit-1(systemd, libpam-systemd, etc.)
Packages to avoid like plague - policykit-1(0.105.5 or later) - Unlike others who are helpful about reducing unnecessary systemd dependency, the maintainer of this package is vehement about keeping libpam-systemd(and dropping seemingly still working consolekit) dependency to this nearly essential package for desktop(see bugreport #747105 yourself), libpam-systemd - this package depends on systemd directly even with systemd-shim present on system.

I have no scientific data to back it up, but I strongly suspect both CFL and LED's premature burnout problem arises from using cheap,low-grade capacitors(Both needs capacitors for power conversion circuit). And I think LED last longer than CFL just because LED draws less current from that same cheap,low-grade capacitor so that it's less damaging to that crap.

There is more than one way to do it.

1. Raspberry Pi(not practical)
RPI+linux+iptables+openvpn
pros : cheap, low power(5W), no noise, low heat
cons : 1 100Mbps port only, usb-ethernet/usb-wifi+additional switch needed, usb performance not good. Not recommended unless your outer ethernet side is very slow.

2. DD-WRT + supported hardware(ap/router)
AP/router(typically arm based)+linux+iptables+openvpn
pros : relatively cheap(depends on hardware model), low power(typically 10W), no noise, low heat, integrated WIFI/wired ports. small. clean looking.
cons : limited internal storage/memory. May brick your hardware if you are not careful enough(and void your warranty) useful for dedicated role(firewall, vpn)only
                    may use for printer/file server or other role if your hardware has usb port, but (typically) slower than full pc.

3. Mini ITX based PC
Low-end bay-trail based Mini ITX motherboard(j1800 recommended)+dc-dc power+12V power brick+small case+storage+linux/bsd(?)+iptables/pf(?)+openvpn
pros : versatile(file/full printer(cups)/application(ex. minecraft) server capable depend on configuration, up to 8/16GB ram + TBs of storage),
                  still can be made fanless&no noise if you've planned well,
                  relatively low heat(warm) if you leave it on open space
cons : most power hungry(~15W, depend on configuration), additional usb-ethernet adapter/switch/wifi needed, biggest of all above(20cm*20cm*5cm + brick)

tips
-for cheap 12V power brick, look for power brick for LCD monitors(12V 3.5A/5A SMPS - depend on your system's power usage- widely manufactured)
-about iptables, read iptables tutorial on frozentux.net
-p910nd - light, spoolless(no file operation) print server daemon. turn your cheap usb only printer to always-on networked printer even on limited storage platform.

attaching some additional pieces of hardware like some rubber, plastic pad, spring ,small stick to make it behave like real joystick? I remember that there were some hobby projects to make something attached to MSX numpad to make it work like joystick long long ago.

Roughly 3 yrs ago the company I work for noticed that Price of Nylon 12 resin had been steadily rising. Once asked, representative of resin manufacturer said "Oh, they're hugely popular replacing fluoropolymer based plastic(PTFE-teflon I think) in solar panel(in china)." While Nylon 12 is still better than more common plastics for this purpose, it is definitely less durable and cheaper alternatives to fluoropolymer.

Happy to know that bay trail platform finally drops PVR graphics core. Hope that some manufacturer produces small factor platform that I want in 2013.

What I want for my ultimate mobile computing device:

1. Small, lightweight and have physical keyboard
  I walk a lot so I want small device that fit comfortably in my backpack (so that's below 7'') and weight less than 1.5(preferrably 1) pound. I'm not all-day mobile warrior so I can live with cramped keyboard but after testing my wife's galaxy s2 touch keyboard I decided I DO NEED a physical keyboard for typing documents/playing games(like nethack, old dosbox compatible games).

2. MS application/IE compatiblity
    I need to do business with MS office documents and MS IE only internet banking/payment processing. Libreoffice is not good enough if you have to edit/exchange MS office documents with other business entity(and that stupid and powerful entity is stubborn enough that it want genuine MS office docs only and complain slightest of incompatibility problems)

3. Very low power
10W - It will still need fan or huge heatsink. Moving part/high power is not good for longivity/ruggedness let alone battery life. My estimate is that you'll have to go below 2W to acheive compact & sleek design without fan/huge heatsink - Yes atom Z5XX do that and I have one now.

4. usable graphic core without fsckup.
I need graphic core that supports linux well and play angry bird. PVR core in atom don't support either. Even their xp driver don't support basic opengl well enough.

5. Support basic net tools/secure net connection I feel comfortable
I want to redirect all normal net connection via VPN using my secure home base using openvpn when I connect to untrusted/public wifi. I believe that is reasonably achievable(without heavy source modifying/manually recompliling) with only linux/winxp~7 for now. And I hate OS that don't support basic net tools.

6. Trusted application that I know What it is doing.
I don't want application that does unknown things behind my back(leaking private info for whatever reason or doing net connection I don't want it to do). So I prefer well known/open source apps and become skeptical on many android/google apps.

If you go ultrabook route, you can acheive 2,4,5,6 for now.
If you go atom route, you can achieve 1,2,3,5,6 for now. Currently I've settled for this.
If you go arm based smartphone/pad route, you can achive 1(depends on device),3,4,may be 5 (if you rooted your phone/pad) for now.
With WINRT device, may be you'll be able to achieve 1,2,3,4.

Of course things are changing so somewhere in future may be you could do things with a platform that counldn't do for now(compatibilty/standard compliance got better,intel finally make 2w non-atom processor/drop FSCKING pvr core from atom, better performance to run emulation comfortably, corporation changes their mind about privacy...). So I think it is the race between platforms which acheives the most within reasonable time.

We sacrificed creativity, and some unknown possibility for the security fit for dumb majority.

Look at the picture of this board. Unlike typical atom330+945gc nettop board it has NO FAN. And if we recall the fact that 945gc chipset consumes 25w of power, way more than 8w cpu itself, I would rather call this board "Nettop ATOM board done right, powerwise". So if you already have netbook which uses 945gse mobile chipset(which is already power efficient), this would mean nothing more than minor facelift. But if you're going to buy atom330+945gc itx nettop board, this is much improved product to consider regarding power. And minor upgrade from gma950 to gma3150(slightly improved g31), would be better than nothing.