Phone unlock cards

Omnutia

Phone unlock cards (for want of a better name) are things I came across a while ago but as more of a curiosity than a serious consideration. They are a chip on a very thing circuit board that you place between the SIM card and contacts. They then, somehow, remove the phone lock without any modification to the phone. The problem some of them have is that, in some phones, there is not enough room to have the chip so they require cutting a section from the unused end of the SIM card.
I was thinking of getting a few to have around if I ever needed them.

Here are a couple of examples 1,2 (I wouldn't recommend buying from DealExtreme, bad customer service.).
Has anyone else ever heard of these or had any experience with them?

Apreche

That seems like a pretty dumb idea. It's much easier to just get unlock codes and type them in.

Omnutia

That's odd to hear from you, Scott, you're usually so positive about things. These seemed like a better idea to have around, as you could unlock a phone on the spot and, as long as you buy them before hand, are more convenient and cheaper.

Apreche

That's odd to hear from you, Scott, you're usually so positive about things.These seemed like a better idea to have around, as you could unlock a phone on the spot and, as long as you buy them before hand, are more convenient and cheaper.

Unlock codes could be free and easy if people who had them didn't keep them so close to the chest.