I have a jailbroken iphone and I love winterboard and iblacklist. Those two apps alone would draw huge sales if they allowed them on the app store, but I understand apple's policy with running apps in the background (i.e iblacklist). I don't buy the hype though about the battery drain running apps in the background. I can get easy 2 days of excessive use (constant internet surfing, flycast-streaming audio, watching movies, talking on the phone). 4-5 days with less than average use so I think its more of a control thing why they limit the SDK so much. I liked apple better when they were just apple computers.