I did some research this week. I found that on most of my UK credit and debit cards (Santander, MBNA, Barclays, etc) you can effectively disable the contactless feature by damaging the antenna. This is very easy and will NOT affect the Chip-and-PIN feature that s relied upon for ATMs and in-store purchases. (DON'T FOLLOW THOSE STUPID YOUTUBE VIDEOS THAT DRILL OUT THE VISIBLE CHIP!!!).
All you need to do is use a pair of scissors, make a small vertical cut of around 7mm at the top-middle of the card - just above the magnetic stripe. If you look very carefully into the cut you will see 4 or 5 very small wires that have been severed. Job done.
Without the antenna loop, the contactless chip cannot energise and communicate.
See my blog post on this in more detail: http://linuxcentre.net/disabling-contactless-cards
I've just been doing this using dansguardian and squid with some extra blacklists+voodoo for a primary school (ages 5-11) these last two weeks. See http://linuxcentre.net/wiki/index.php/Web_Content_Filtering . Personally I find this kind of filtering not completely effective - even the best commercial filters out there are no better in 'protecting' the kids. This was a lot of effort for 100+ children. You probably wouldn't want to go to so much trouble for a home setup. However, the above link does represent a real-life setup and not just a theoretical setup.
I worked on this project for a Primary school. It's worked well for >2 years for 120 pupils.
The parts about automatically resetting the homedir after reboot is probably of interest to you.
http://linuxcentre.net/wiki/index.php/Detailed_Maverick_Meerkat_OS_Netbook_Customisation below Home_Directory_Synchronisation
xrdp on Linux works for me - not quite as fast as NX but certainly better then VNC variants I have tried.
Yes, me too. Been using dovecot and Maildir files for years now. Before that I used a different open source IMAP servers (courier, cyrus, and UW imap) but since I used Maildir file format the transition was automatic (I used mbox format before that with UW imap server and conversion was really simple using the mb2maildir perl script). I have used IMAP servers etc for 18 years worth of email. I organise the 250,000 emails into different folders for each year as that makes searching much quicker. It's never let me down yet.
I've used an Acer Revo Intel Atom based nettop. It sucks about 20-30W... I use it as my main desktop which also runs samba, bind, dhcpd, ssh, dovecot and postfix. Works a treat with Fedora11. I had exactly the same motivations and now am saving around $150 per year. The system cost me around $270 including extra 2GB DRAM.
In any formula, constants (especially those obtained from handbooks) are to be treated as variables.