As I received my Ipod Touch a few days ago..
I immediately searched for any dreaming apps, or podcasts..
and came across this beauty which also happened to be available on youtube for free:

http://www.youtube.com/stephenberlin
At first I was a bit sketchy because it had such a horrible picture at the start but I was rather surprised by the quality.

It's a series of 11 ten minute videos about dreaming in general, lucid dreaming and a few of his own experiences and dreams.
(He doesn't teach how to lucid dream however.)
I thought it was worthwhile to mention on the forums.
(I know it has been posted in 2007 before, but I thought it was good enough to announce once more.)