Sun have announced that they are going to introduce flash based disks. You can try this yourself with a USB Flash drive, but before you do, you should be aware of some of the pitfalls discussed yesterday by Jeff Atwood on Coding Horror (for example, he says "USB flash drive performance, even for the best models, is a small fraction of typical hard drive performance".
This shouldn't be an issue for Sun though, as they are using an "array" structure according to the press release.
For the Coding Horror article: http://www.codinghorror.com/blog/archives/001127.html
For the Sun Microsystems article http://www.sun.com/aboutsun/pr/2008-06/sunflash.20080604.1.xml