Boy another thing I love about reading books on my iPod Touch with the Kindle app is all the FREE ebooks Amazon offers for their Kindle! (Yes, you can read these on you iPod Touch (and iPhone, iPad and Blackberry)
I've got a ton of free Kindle books already, but I check every day to see if there are new ones I might be interested in. I've got this link bookmarked: Amazon's Top 100 Free Kindle eBooks