One of our readers left a comment about a free application for AMERITRADE clients that allows you access to your account on the go. MarketSimplified looks like the most powerful trading application for BlackBerry to date. I have not had that long to play with it but it packs a bevy of features that combines everything from streaming quotes to your watchlist. It even has a great dashboard for a quick snapshot view of your positions.
You can read more about the features at this link or qualify for the free application with your AMERITRADE account. So far it seems to support the 8300, 8700, & 8800 but no word on the 8100 or Bold.