I just wrote a post on my blog about how to use curves in Photoshop. It goes over some of the basics of what can be done with curves, and how to accomplish it. There are a couple of YouTube videos, and a before & after shot of mine demonstrating how powerful curves can be. Hopefully it helps some of you out there. If you have any question, comments, or suggestions about topics you'd like to learn about in the future, please let me know and I'll make a post about it.