Wanna send money from one iPhone to another? Let 'em bump heads.
PayPal's latest update of their iPhone app includes code from Bump Technologies, essentially allowing one iPhone to transfer money to another iPhone by tapping the two phones together. (Think of it as a more, um, tactile version of the old Palm Pilot infrared-beam data transfer.)
The app upgrade also lets you send a request for money to one of your contacts, as well as transfer funds from your PayPal account to your linked checking/savings account. PayPal also plans to upgrade their Android and Blackberry apps in the very near future, to keep in step with the iPhone upgrade.
Download the app for free from the App Store.