So I'm going to college for Computer Science and as I was walking to the bathroom I saw we had classes DEDICATED to Mac specific activities. Now I have one thing in mind. What do I need to learn to make worth while iPhone Apps? I don't mean Pong-ish like games and etc. but actually useful programs that people will be intrested in buying. Right now we still have a couple months left before the semester is over so I want to learn on my own before I get into any classes. From my understand I should ....learn Cocoa, Objective C, and Java? Any help on what I should learn and what books I should get in order to be able to code some useful apps. Thank you!