I had been using 3 applications on my Nokia N900, using a different one for some of my twitter accounts. Witter for my personal one, Mauku for a fun one and TweeGo for my work-based account. Unfortunately since Twitter removed access for any applications not using OAuth, Mauku and TweeGo have stopped working. I had hoped that the developers would update their application, so that I could keep 3 open at the same time and therefore keep tabs on my different accounts. Unfortunately that is not the case and I now have to relying on Witter and web access now!