I can't believe this hasn't already been requested or talked about but I can't find anything in the search.
What I would like to see is a proper portable Twitter app.
I know you can use a add-on for portable Firefox or the IM bot for use with Portable Pidgin, but nether of these offer the features of a dedicated twitter client (such as Twitteroo for example).
I have also searched the web ("Googled") for a 'portable' twitter but haven't been able to find anything which would fit the bill.
If anyone has I am happy to be corrected!