Apple Thoughts: USB Fever Releases Sim Unlock Card

"This Sim Card is the Latest in the Line of Smart Technological Solutions to By Pass Network Restrictions on Mobile Phones So You Can Be FREE To Use Your Choice of Network Simcard with Your Mobile Phone, without getting your phone unlocked. In simpler terms this Simcard enables your existing simcard to work on any locked mobile phone. It is used in parallel to your existing simcard as its only 0.10mm thick, therefore can be inserted along with your existing simcard in any of the mobile phones available throughout the world. It can also be removed easily, without causing any damage to your phone."

Do I know if it works? Nope, but I've heard of similar products in the past that do a similar job. Obviously try it at your own risk, but if you're not happy with the idea of jumping on the AT&T bandwagon but still would like the iPhone 3G, this might be your best bet until a software unlock is developed.