Unlocking cell phones

We have 2 cell phones - Samsung SPH-m530 and a Motorola V220. I seem recall reading on the board where a good place to get them unlocked, or at least checked to see if they are compatible with the MX carriers. Can someone please point us in the right direction? Apologies I did search to no avail. Thanks
PS Bob, when's the next swarm?? New in town and would like to meet the faces behind the avatars.

CanuckBob wrote:We are thinking about another swarm in late July. Probably around the 22nd or so. Stay tuned.

Thanks, Bob. We'll be watching.

Also, we stopped at Telcel on the Libramiento and were able to open an account for an old cell we brought down with us.

I had an iphone unlocked at the little Telcel shop on the side street between Buganvillas Plaza (El Torito) and Marissa's bakery.
Go one block south on that side street and it's on the west side across from the garage.
Very helpful and speak English also.