TechSpot posted a guide about setting up Ubuntu 10.04 on a Bootable USB Flash Drive

So, you've been hearing all this buzz about Ubuntu for a while now and you finally want to take it for a spin? While dual booting Ubuntu with Windows is fairly straightforward, it can seem like a daunting and risky endeavor for the average individual. For those folks, test-driving Ubuntu via the LiveCD is certainly an option, but it comes with a couple major disadvantages: it's a much slower experience, and all your changes are lost once the operating system is restarted.

Besides a traditional installation, you can get around these limitations a few ways, one being with a virtual machine. Naturally, going that route means you'll have to download and install VM software, but this isn't viable for everyone not least because of hardware constraints. Another even simpler way involves creating a bootable USB flash drive with a fully functional copy of Ubuntu installed.

In addition to being speedier and letting you save data, creating a USB boot drive also allows you to take your installation of Ubuntu wherever you go. It should run on any machine that supports booting from USB -- which is just about every semi-modern PC you're bound to come across. It may sound complicated, but fret not, if you already have an Ubuntu CD, you're literally a few clicks away from creating a USB boot drive.

Test-Drive Ubuntu 10.04 Using a Bootable USB Flash Drive