A bootable USB stick also gives you the ultimate portable computer: A self-contained Linux desktop system that will run on any PC that supports booting from a USB storage device. And unlike most Live CDs, a USB or flash drive allows you to create persistent custom desktop settings and to store your documents and other files.
Currently, at least two major Linux distros make it easy to create a bootable USB device: Ubuntu 8.10 and Fedora 9.
This week, HowtoForge, one of my favorite Linux help and support resources, posted a great illustrated guide to creating a bootable USB stick using Ubuntu 8.10. The guide is clear and easy to follow, with plenty of screen shots, including help adding the persistent data-storage option.
There are still a few things to keep in mind before you get started. First, you'll need access to a PC running Ubuntu Linux 8.10. Second, you'll need a USB stick, SD card, or other flash memory device with at least 1 GB of space. (If you plan to store data and files on your bootable flash drive, be sure you'll have enough space for those, too.)
Third, and most important, remember that the host PC must support booting from a USB/flash memory device, and that option must be enabled in the system's BIOS. This may be a problem on older systems or when a sysadmin has locked down the BIOS for security reasons.
Also, remember that your USB Ubuntu Live distro also gives you the option to do a full Ubuntu installation to a host machine, which makes it extremely handy for netbook owners who don't have ready access to an optical drive.
Last year, Lifehacker.com published a similar guide to creating a bootable USB drive using Fedora 9 -- the cost-free, community-supported version of Red Hat Linux. The Fedora Live USB Creator, however, offers one big advantage: It runs as a regular Windows application. This tool will create a bootable USB drive using an existing Fedora Live ISO image, or it will automatically download a copy for you
As the article points out, when you're done, you may have to tweak the USB drive's partition-management settings to make it bootable, but this problem is easy to fix (from a Windows command line) if you run into it. In addition, many of the same caveats I mentioned before about USB drive capacity and BIOS settings also apply here.
Finally, keep in mind that traditional Live CDs are still a great option for trying out Linux distros on PCs or laptops with optical drives. Right now, the LiveCD List shows 315 Live CD/DVD options, so you're not likely to get bored anytime soon.