On the last day I had just enough time to listen to Eric Smith and Eric Meyer from 8th light where they talked about TDD with IPhone. What was interesting was even while working with this difficult technology (Objective C is not hard but Xcode is nothing but cryptic - XIB files really?) they were able to build iPhone apps without giving up of basic principles of TDD.
They demonstrated their struggle before any tools were available for Unit testing with iPhone.
Couple of tools they mentioned were
Google Toolbox for the Mac
OCUnit
Something to make life less miserable when building better applications with iPhone.