Apple has put videos of the developersessions of WWDC 2009 online. There are dozens of presentations, and a large amount of those presentations are about the development of applications for the iPhone. Each video is around 150MB large and can be viewed for free, if you are a member of the Apple Developer Connection. Last year, the entire pack of videos could be bought as well, but as a non-developer you had to pay $999.

A nice advantage is that the sessions are available so quickly after the WWDC. Last year it took almost half a year before they were published and that had the downside that some info was already outdated.

The videos can be found at Apple Developer Connection, but you need to log in.