Online Word Processor
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