Running multiple Auto-Twitters

I'd like to run multiple twitter programs at once.

I have one pc.

Could I get a variety of Twitter programs, eg - TweetAdder, BirdyAdder, whatever else I can DL and run them all from the same PC, with different Twitter users? (I think some of these support proxies, TweetAdder does at least)

Or, could I run multiple Virtual Machines on the one box, doing essentially the same?

Does anyone else use more than one twitter automater simultaneously?

Cheers