Unlocking SIM on Cingular 8125?

[rookcnu]

I have two questions about unlocking my Cingular 8125 SIM:

1. If I unlock it, can I re-lock it some other time if I want?
2. What carriers can I use on this phone on once I unlock it? Is it any carrier? Will it work on Nextel or Alltel?

Thanks!

[Sven Johannsen]

You don't unlock the SIM, you unlock the phone. You get a new SIM from the carrier you want to use. That starts to answer part two. You need a carrier that uses SIMs, and those are typically those that use GSM, not CDMA.

[jadesse]

You have two choices AT&T or T-mobile.