Griffin has quite the iTrip legacy, and though the company was a pioneer for iPod-friendly FM transmitters, the signal strength has been a weak point. Unfortunately, the issue has not been remedied in the iTrip Pocket, an otherwise lovely device with an ultracompact design and friendly user interface. Still, if you live outside the urban jungle and want a transmitter that can double as a keychain, the $49 iTrip Pocket could suit you just fine.
Measuring in at 1.6 inches wide by 1.1 inches tall by 0.2 inch thick, the iTrip Pocket is indeed smaller than a book of matches and just as thin as the iPod Nano. A 30-pin connector jutting out of the top allows you to connect it to any dock-connecting iPod, and the iTrip Pocket will output its tuner display to the player's screen. On the front of the transmitter are four buttons: one long tuner shuttle key for scanning through frequencies and three numbered preset buttons. There's also a tiny LED that lights up red when the unit is on. The iTrip comes with a clear plastic cap that features a hole through which you can string a key ring.
Operating the iTrip Pocket is a simple matter: plug it in and turn on the iPod, and the transmitter automatically powers on. Then use the tuner rocker or preset keys to navigate to an open frequency. However, probably due to its small size (and--as a result--small transmitter), the iTrip has trouble holding on to even the weakest stations. So unless you have a completely vacant channel in your area, expect frequent static and dropouts.
During testing, we tuned the iTrip to 88.1--a channel that both the Maximo SAN-360 and the DLO TransPod had no trouble locking onto throughout San Francisco--but we received almost constant static and suffered from several dropouts. It wouldn't even transmit to other near-vacant frequencies. In the few instances we received some uninterrupted music, audio quality was acceptable, so if you live in an area with a lot of open channels, the iTrip Pocket could be an OK choice.