The illegality of it stops approximately nobody as it stands, so this would do approximately nothing. The problem is not that it's illegal to do an end-run around the carriers, but that it's technically very difficult. Their locking mechanisms are constantly improving. For example, I'm not aware of any recent iOS release or iPhone version that has been unlocked without somehow involving the carriers or Apple.
There are SIM interposer devices ("a thin microprocessor that sits between your network SIM card and the base-band hardware") that can unlock an iPhone 4S on iOS 6: http://www.applenberry.com/gevey-ultra-s-gsm/ - that's the latest that I know of. I have no idea whether the DMCA applies to them though.
Oh yeah, I was aware of those but hadn't kept up with them and forgot to check on that when posting my comment. Nice that they've kept up with OS releases, although they seem to still be a bit hit-and-miss as to whether they support a given OS release and iPhone model.
