I found this article today giving the pros/cons of recording to an iPhone directly.

The two hardware options considered are the Blue Mikey and the Alesis Pro Track, which I reviewed last year.

I don't think I could have written a better article myself, so that's why I am sharing this one in my blog.

We are close to this being a viable option, but I don't think we're quite there yet. One important problem with the concept of something like Source Connect on the iPhone is the fact that many audio interfaces require you turn off the network connection to keep the radio from interfering and making nasty noise on the recording.  Maybe the iPad will become the weapon of choice, but it's way too early to tell.