Sometimes i find myself in the need of getting some OS up and running quickly, just to try some stuff out. Like Live CD images of various sorts. Lately i've found myself playing around with
SLAX, a live Linux Slackware, with a file system that can exist on a USB flash stick on FAT32. That way the stick still is useful for other things (ie. using it as a normal stick from other operating systems that can mount FAT32 partitions).
Incidentally
BT3 (an security auditing tool) is these days also is based on SLAX.
I have yet to find a way to make
VMWare player (the free version of VMWare Inc's popular virtualization software) boot from the USB device.
There are several sources on the world wide web explaining how to customize the VMWare player, but i'll just recap my base configuration file, and other hint's that might be useful for customization.