I have not yet bought my iPad. I have an iPod classic and have a good number of mp4 movies I can play on it.

2 questions:

Does the Codecs and dimensions that work on my iPod also work on the iPad or do the mp4s need to be reconfigured somehow?

assuming they will play on my iPad, I have heard that with some apps like Streamtome or Air Video, I can play on my iPad mp4s that are on my external hard drive! This is MAGIC! Does anyone have experience with this?