Cyanogenmod is an awesome aftermarket Android ROM that you can
put on your phone to get an experience closer to the stock
Google experience. I use it on my Samsung phone because I don’t
want to deal with Samsung’s weird bubbly UI.  All the people
working on Cyanogenmod are phone nerds who aren’t getting paid,
and even though their documentation is a lot better than you’d
think, there are still a lot of questions that it’s hard to get
straight answers to. Right before my last trip to Japan, I
didn’t know whether or not Cyanogen supported GSM mode for my
Verizon Galaxy S3 (i535 or d2vzw), so that I could use it with a
B-mobile SIM in Japan.  This isn’t the sort of thing you can
Google around to find out- you have to spend a lot of time
working your way through arcane XDA-Developers threads and
there’s a lot of outdated/self-contradictory information in
those.  Anyway, here’s the deal. If you have a Verizon phone and
you’re running Cyanogenmod 10 or 10.1 (CM10 or CM10.1), as long
as the phone has a GSM antenna y