Photosmith Syncs iPad with Lightroom
Photosmith lets you tag, rate and otherwise organize all of the photos which you have imported into your iPad, whether using the camera connection kit, an Eye-Fi card or just saved from an e-mail. This means that you really can leave your laptop at home when you go out shooting, or away on vacation.
Link: Photosmith Syncs iPad with Lightroom | Gadget Lab | Wired.com