I sometimes listen to the podcasts done by Jeff Goldsmith, senior editor for "Creative Screenwriting" magazine. Recently he interviewed Michael Ardnt, who is the writer of "Little Miss Sunshine"and I highly recommend downloading the podcast. You can find it in itunes by searching in podcasts for "creative screenwriting".
You'll get more out of it if you've seen the movie, but even if you haven't there is some great stuff about general moviemaking and character development. Warning: there are spoilers involved so if you haven't seen "Little Miss Sunshine" yet you might want to wait until it comes out on DVD and see the movie before listening to the podcast.
The beef I have with most screenwriting resources in general is that they usually concern things that aren't related to story, stuff which is probably fascinating to writers trying to break into the business but kind of irrelevant to those of us who are only concerned with the workings of story. Usually screenwriting interviews focus on topics like how to get an agent or how to get your script in the hands of an "A" list actor.
The interesting thing about the Michael Ardnt interview is that Jeff asked a lot of those kind of questions but somehow Michael seemed to answer each one and at the same time he managed to work in tidbits about story structure and character development along the way. I listened to the podcast while I was driving to work and I found myself constantly pausing the interview to write down notes on what Michael had to say. I still have a few minutes of it I haven't listened to yet so if you see me on the freeway tomorrow morning you might want to give me a wide berth.
Anyway the best part about the whole thing is that it's totally free so go check it out! Isn't the internet cool???