I want to learn openGL, so I could make some iPhone games. I'm already comfortable with objective-c and cocoa touch, so I don't need any help there. What I'm wondering is if any of you could recommend a good book to start with, or some other good resource. Should I get an openGL ES 2.0 book? I'm not really interested in programming for older devices besides the iPhone 3GS and up, so would that be good? Or should I get an older openGL ES 1 book? Should I get a regular openGL book instead? I want the most up to date book that is good, and one that would be easy to apply to iPhone development. In other words, I don't want to learn one thing, than relearn it in another way. Thanks for your help.