You could make AbiWord ultra-portable if you hosted it online. Is there a way to make it available for use online with save and open functionality? This may seem a little far-fetched, but it would eliminate the need to carry it with you on a drive. In fact, if it is possible with AbiWord, then you could put OpenOffice online, (OOoO) and it would even eliminate the need for office software installed on a machine.
-Justin
Here ya go...
http://online.thinkfree.com/
You need Java2 loaded, so it won't work with Portable Firefox unless Java is on the local PC, for example. It's BIG... bigger than downloading Portable AbiWord... so the download takes a while.
Sometimes, the impossible can become possible, if you're awesome!
http://www.writely.com/
I'm working on the PortaFTP suite (see my signature); it would let you run apps from your FTP server (if you need one, host one on your home comp). Would that be useful?
Otherwise, just use AJAX.
~nm35 {blog} {projects} {standalone apps}