We've seen the iRig and the AmpKit, two interfaces for getting a line-in from your guitar or bass. Both come with effect racks and sound pretty darn good. But where do you go from there? How about a dock interface that records 44.1 kHz, 24-bit audio without line noise? Apogee's Jam guitar interface does just that, and it throws in hardware gain control and LED peak monitoring. It plugs into your Mac, too!
I saw something similar at Macworld, though I don't think it was this particular model. I sat down and played an acoustic with pickups through my iPhone, though, and I was blown away by the clarity of the audio. The dock connector is, in my newly-formed opinion, the way to go. The problem at the time was that it didn't come with any effects, and the convenience of the AmpliTube and AmpKit setups was more convincing to my limited budget. However, with Apple's announcement of GarageBand on the iPad, the tables have turned.
GarageBand's full set of effects, combined with a crisp guitar input, plus editing and multi-track capabilities (all with the polish of an Apple product) make this an amazing prospect. I'm sure I'll be picking one up, as they'll be retailing at US$99 and will be available later this month. See the Jam page at Apogee's site for more info.