TweetyStock iPhone app: follow your stock portfolio on Twitter
TweetyStock's extensive features all work within the app; there's no need to open links in MobileSafari. For your 2 dollars, you get Twitter feeds and regular news feeds for your whole portfolio, or just a single stock. You also get two kinds of charts, and a basic table that shows at a glance whether your stocks are up or down. TweetyStock makes Apple's built-in stock app look a little shabby, especially if you're a serious trader.