Hi, I'm considering buying an Android phone, is there anything I should pay attention to about the OS version, licensing, how upgrades work, etc.? Do different carriers "curb" functionality or access to the market, or delay updates? Do you have different access to app markets (or other ways of installing apps) depending on the phone? What kind of extra functionality do you get by rooting/flashing, and do some phones (like the Nexus One ... others?) have it out of the box? Can rooting/flashing be discouraged / blocked by certain carriers? Is there a small guide on this sort of stuff somewhere on the net? Wikipedia didn't say much, and I don't know if that's because there isn't much variation from phone to phone or just because it's incomplete.