I am looking for a distribution that can run the entire OS from a flash drive.
This question is NOT about being simply able to boot and/or run OS from a USB stick: what I am looking for is a distribution that specifically targets flash disk as a boot media. One example of such a distribution that comes to my mind is Android; however, I would prefer something that I could use on a server.
edit: I feel I must explain myself, why I wrote this post. I am aware it is possible, and quite easy as a matter of fact to install many distributions onto a USB flash drive. What flash drive is missing (if you compare it to SSD) is the wear-leveling smarts built into SSD firmware. But my logic was, that this should be possible to emulate wear-levelling logic using software, this is why JFFS, YAFFS, LogFS systems came about. What I am looking for is a distribution, which is made to run from one of those systems.