Hello Android/Captivate gurus! New to the forum here, and new to smartphones! I was initially looking to get an iPhone 4 but eventually ended up with a Captivate that arrived today. I wanted to get a hang of the phone first just using wifi (which I have most times in the day) vs 3G , so I did not get a data plan yet. What settings do I need to check so that I don't inadvertently use 3G for data and rack up a ridiculous bill? Thanks!