OS on a stick
An entire linux OS distro that's been optimised to run on a thumbdrive -- a 128mb thumbdrive to be exact, though of course you could use a bigger one for more storage. Includes a lot of apps like AbiWord (compatible with MS Word), GNumeric (compatible with Excel), GXine, Mozilla Seamonkey Suite, etc. Everything loads into RAM, which makes it fast, fast, fast
I give you Puppy Linux.
I give you Puppy Linux.