Generally, Arduino is a good way to interface the physical world with software. Other commenters mentioned an autopilot and a 3D printer, both examples of controlling motors or servos with software, based on sensor input.

One project I did was for controlling stage lighting, with programmed sequences of effects being "DJed" in real time. I prototyped an out-of-band management interface for web servers. It could power cycle servers and provide console access. I used a similar system to have computer controlled Christmas lights and 4th of July fireworks.

Another project was controlling a CD burning robot, to burn hundreds of CDs.

In general, pretend you had a robot that could run around doing anything you want, controlled over the network or pre-programmed, so the software side can detect the environment through sensors and then take physical actions through its gpio.

Slashdotters know about a lot of different small hardware.
Suppose you wanted to build a gas pump controller with a touch screen based on Android.
One issue is that in order to protect customers before certifying the pump, the department of weights and measures wants to see that the gas station owner can't easily manipulate the device to show an inflated reading. What kind of hardware would you consider?

The benchmarks I've read, which were reviewed by the kernel mailing list, indicated that dm-cache has the best performance in many cases. My gut feeling is that I'd rather use bcache, but I don't know why.

The current benchmarks have one huge failing, though. They test random IO by doing truly random IO all over the disk. Real random writes, in real workloads, is concentrated mostly in a relatively small number of blocks, such as the database and log files. That's important because the caching systems put the frequently accessed blocks in cache. True random benchmarks, with no blocks being frequently accessed, counteracts what the cache is doing. What's needed is a set of benchmarks run with random IO within four files of a few GBs each , to simulate a database, mail store, or other frequently accessed region of the disk.

Okay I chose a bad example. On the other hand, I've been to fairly large conferences where reliable bandwidth was an issue. IA2000 comes to mind. I wouldn't be surprised if organisers and vendors could use backup / more connectivity at events like certain Ren Festivals. A few months ago an event organizer posted an Ask Slashdot about bandwidth for a pot fest of some sort, maybe a reggae festival, I don't recall exactly what.

Google will bid $ pi billion for whatever spectrum they find suitable. :)

You keep posting that crap for every other article.
You're being sarcastic, right? You know tea party people think government is basically incompetent, incapable of say, launching a shopping web site, right? Conspiracy theorists, on the other hand, believe the government is secretly controlling everything, that they run everything. So pretty much opposite ideas of what government is. Here's a cheat sheet for you:

Believes government is incapable of setting up an insurance shopping web site: tea party
Believes government can hack your phone to spy on you with the battery removed: conspiracy theorist

Funny how rather than the realistic idea that the organizers of an event might have use for internet access, TFA assumes some ultra-rich lady would bring her own internet. At say, the Super Bowl, do you think maybe the broadcast crews, the security team, the merchandising companies etc. might want reliable internet access? Nah, I'm sure just some random guy in seat 44K would be the customer.

This author sure had to work hard at playing stupid to come up with this attack against Google, didn't they.

I said "for some workloads" twice. Specifically those "localized" workloads would include a web server with a MySQL database, a mail store, or other frequently accessed files - a very, very common workload. The database and other frequently accessed files end up on SSD while the large, sequentially accessed files such as videos stream from spindles.

I also said "up to" - in some cases it might not be 100 times as fast, but "only" ten times as fast.

  For some common types of workload, bcache (or dmcache) makes a big difference.

Bcache, merged in 3.11, improves IO up to 100X. Not 100%, 100X, or 10,000%. It may well be worth an upgrade if you're running a distro 2.3x and have random IO on multi TB storage.

If your default browser is IE, every time you click a link to an html page Chrome should launch IE, ignoring the fact that you've explicitly decided to use Chrome at the moment?

No? How about a jpeg, as Dahan said? Should Chrome display the image, or open Photoshop?

What's the difference between opening Adobe's software for jpegs and opening Adobe's software for pdfs?

The point is, whatever operation you want the hardware to perform, it could do it to the whole system extremely quickly. Some examples:

At boot, it can load the entire system into RAM in under a second and never wait for a read from the flash drive again.

Next, it could download an update which replaces every file in the entire OS in less than 5 seconds.

A virus scan of the OS takes less than a second.

A complete backup takes less than a second.

Opening the web browser takes less than a millisecond (it was duly loaded into RAM during the 2 second boot .)

Searching the whole system for any files named "foo.lib" takes less than a second.

For transporting documents intended for print, or intended to look like standard size printed paper, off does a good job, and there's a reason for that.

For those unfamiliar with the history, Postscript is a popular language for computers to talk to printers. Windows, Mac and other computers could all speak Postscript. "Print preview" functions could also read the postscript commands to display a print-like view on screen. So if you wanted a platform independent document, you could just use those Postscript printer commands, zipped for smaller size. That's essentially what PDF is - a dump from a printer cable, zipped. There's no need for "select top tray" and similar printer commands that don't show on screen, so those aren't valid in pdf.

So yeah, pdf is good for printing because that's what the language was originally designed for.

* The above is of course a summary. Pedants can of course point out various changes from postscript to pdf.

My natural instincts tell me that bacon slathered in gravy and topped with cheese is delicious. My natural instinct says "I'd hit it" about eight times a day. My natural instinct is to punch that asshole square in the mouth.

I have a brain capable of rational thought, though, so I eat vegetables, sleep with my wife, and refrain from hitting people.

I hope you're not so cruel as indulge all of your cat's natural instincts.

For that matter QNX, a complete graphical OS including essential programs like a web browser and even a web server is a couple MB - smaller than many odd DOCUMENTS.

I wonder how blazingly fast a 4MB OS is on 4GHz machine with GBs of RAM. The CPU could process the entire OS in less than a millisecond.

There was a contest for the smallest program that produces as output its own source code. Count the characters in the winning entry, which follows:

AC's comment.
Slashdot's we site.
It's thing? No, its thing.

Damn it, I've been doing it wrong all this time. Damn English. Maybe "Ive" been doing it wrong; I don't know any more! Maybe I dont know. Crap.