USPS is out with its own iPhone app, allowing its service users to perform a number of tasks while on the move. For instance, you could locate nearby Post Office, Automated Postal Center and Collection boxes – and get driving, walking or mass transit directions to the selected destination.
Moreover, there’s the Track and Confirm feature that provides a visual monitor of the progress of the mail pieces and requires only initial input of tracking code numbers so that follow-ups are only one click away.
In addition, in case you don’t know your ZIP code, you could easily find it out as the app uses your current location as a parameter.
Finally, it’s worth adding that in addition to the iPhone app, USPS is working on a mobile client for other platforms. And whenever I hear other platforms in the U.S., I think of Android and BlackBerry. However, no dates were given for those two versions…