It took Apple Inc. more than six months to build up the iPhone, but curious gadget fanatics needed only minutes to tear one apart.

Within hours of the first iPhones going on sale Friday, enthusiasts scrambled to be the first to discover what makes the devices tick, posting photos and videos of disassembled phones on the Internet.

The information is more than just academic. Apple keeps a tight grip on information about parts suppliers, so "teardowns" of its products are closely watched by investors keen to figure out how to place their bets.

Opening the iPhone was the easy part. For many, the real prize is hacking the phone to get it to do things Apple never intended, such as run on networks other than that of AT&T Inc., the exclusive U.S. service provider.

Some programmers also want to find a way to run their own programs directly on the phone's operating system rather than being limited to programs run through the Web browser.