You may soon be able to share iPhone apps between friends using a feature called ‘application seed‘. Apple has filed a patent application for such a feature that the inventors think will bring more word-of-mouth publicity to the application.
Unfortunately, this iPhone app-sharing functionality will not mean you can save money by trying out the app purchased by a friend. Instead, this feature will merely transfer a trial version of the original app to the recipient. Worse, the developer can also choose to instead send a link to the App Store to the recipient.
The patent application delves further on the aspect of word-of-mouth marketing noting that the recipient may in turn be able to share the demo version of the app or the App Store link to more users. The sharing is seemingly possible over Bluetooth and Wi-Fi.