I have a first-gen iPhone that all of a sudden looks ancient. Remember when we were all amazed by how thin it was? Anyway, I'm thinking about upgrading to a 3GS, but I have a few questions: 1. How easy is it to switch all of the AT&T crap to a new iPhone? Do you just put in the new SIM card and call it a day? Or do I have to somehow tell AT&T that I have a new phone? 2. Without a SIM card, could I theoretically use my current iPhone as an iPod touch basically? 3. Did they fix the stupid headphone jack so you can put in headphones that curve at the end of them, the ones that don't fit in the first-gen iPhone?