http://iscoresports.com/

Maybe this will be included in iOS4 update, but the ability to quickly re-enter scoring a game at the point left off at after answering a text, answering a phone call, etc. would be very helpful without having to go through game manager.
Because of the time required to re-enter a game I often can't get to responding to texts from parents on other teams about the score of the game I am at and texts from wife (not really a good idea). Yes, I know there is Twitter, but too many baseball dads feel Twitter is for their teenage daughters to use.

Other folks can also keep up with the iScorecast... that is actually the intent of the iScorecast, and it gives a really nice pitch by pitch account of the game in real time. We now support an HTML format of the iScorecast for those folks that are watching on mobile devices.

We will be supporting multi tasking of iOS4 soon.