Peter Garner decided to use his pen drive flash memory device as a portable program vault (sort of like a people carrier without the…ahem….people). Using small software packages garnered from various locations he has managed to store a word-processor, spreadsheet, browser, email client and assorted utilities on his 32MB drive, all of which can operate in a self contained manner from the device.
In the interest of research I have duplicated his work with my own 16MB drive, and managed to squeeze in the browser, spreadsheet, word processor, email client, MP3 player, RSS reader, image editor, MT blogging client and zip utility and still have over 3 MB left for data. Wow! Oh, by the way, a good source of very small applications is TinyApps.
[Update: Oooh look, booting Linux from a USB key.]