There are many interesting and useful things on iTunes U.
If you are thinking about writing an application for the new iPad or the iPhone then these resources from Stanford University on iTunes U may just fit the bill.
These are BIG files, most of the hour long videos are nearly 500MB in size and there are over twenty of them!
There are also accompany PDFs.
If I can find the time I am hoping to go through the materials and write my first iPhone App.