Apple announced today that developers can now use In App Purchases in their free apps. This not only unlocks a new revenue stream for several existing free apps but also paves the way for a new type of "lite" version of a app. No more downloading an app to test it only to have to download the "for pay" version. ("One app to rule them all" - LOTR quote... really!)
Apple also says this should help combat some of the problems of software piracy by allowing you to verify In App Purchases.
To learn more, log into your Apple iPhone Developer account and visit the App Store Resource Center.
If you are a developer currently looking into using In App Purchases in your existing or upcoming fee iPhone/iPod touch app, we'd love to hear from you on your new experience. Cheers!