Here’s one approach to opening up the iPhone:

 One a more serious note, DVD Jon has found a way to activate the iPhone without an AT&T phone plan, otherwise you can’t even play music.

Also, a new PC/Mac tool called iPhoneInterface will have the following features:

• Run any desired application already residing on the phone.
• Control what processes run on the phone (currently implementation is very hackish)
• Move files around on the phone
• Enable viewing of verbose information during the restore process
• Activate the phone without iTunes and without a token