Well, it looks like hackers have been hard at work on the iPhone since it came out and have managed to hack the iPhone to gain access to the filesystem, alter the iPhone’s internals, and to launch custom programs. This has in turn been used to enable people to install custom ring tones and sounds, use the EDGE network from a laptop, and install and run a simple program on the iPhone. It’s unclear whether Apple can/will disable some of these hacks in the future. These hacks are still really only for techies and you may be voiding your warranty. Also, it looks like some of these hacks break visual voicemail and EDGE network access.