Any computer geek worth their salt has to at least know about Linux. If you’re wanting to get your feet wet, here are some distributions to try out without installing by running from a USB key you’ve got lying around.
Most the the disk images you’ll download are meant to be burned to a CD. You can also do that, of course, but what is this, 2003? You’ll need to use a program like UNetBootin to format your USB drive so your computer can boot from it.
Ubuntu is still the most popular distro among the myriad Linux versions, and for good reason. It supports a lot of common hardware and features a friendly user interface (though the new Unity interface in the latest version has caused a lot of controversy). Of course, you can install it to your hard drive as well.
This is one of the original “live” distros, and also happened to be my first foray into the Linux world. The original selling point of Knoppix was that it ran completely off a CD without installing (when doing this was still fairly tricky). Like Ubuntu, is pretty much comes with everything you need. It’s also useful for rescuing files when your regular OS won’t boot. Just stick a Knoppix USB key in and copy the files you really want to save over (while also learning your lesson about keeping good backups).
If you like games, the lack of commercial games like Portal or Halo (at least without running something like WINE) may be a turn-off. But the community has actually produced some decent games. live.linuX-gamers.net offers a sampling, including Nexuiz, a first-person shooter, Frets On Fire, a clone of Guitar Hero, and Battle For Wesnoth, a turn-based strategy game.
Puppy Linux is a live distro with simple requirements designed for older computers. If that netbook or other computer has been gathering dust in the closet, why not dig it out and boot up Puppy. Everyone loves puppies!
Damn Small Linux
Damn Small Linux (abbreviated DSL, not to be confused with the broadband Internet access method) is another live distro that works great on older hardware. They’re not kidding about the name, either. The whole thing is only about 50 MB. It’s also very complete, with multimedia tools, Firefox, and a word processor.
Variety is the spice of life. If you don’t want to stick to one distro, you can download the BKO image onto your USB drive and choose from a menu of whatever distros they’re serving up that day. It does take a while for whatever you’ve chosen to download, though.