I'm looking at doing an application for the iPhone for a software company. They are offering me an iPOD Touch to use as a test unit, even though the iPhone is the target platform. Are there known differences which could hinder my development if I am only testing on a live unit of the iPOD Touch?
Could there be a problem that I might not identify such as using the 3G or 2G stack on GSM problem that won't show if I use only the wifi on the Touch? This is a pretty open question, but this project is somewhat simple, but it could lead to more projects on the platform, so as much information as possible would be best.