I don't actually know anyone who still uses a Nokia phone, but if you do, and you want to unlock it, check out this handy online tool.

Ah, but you have questions: What is unlocking? Unlocking your phone lets you use it on another carrier. So if you have a Nokia from Cingular you could (theoretically) move it over to T-Mobile if you unlock it and put in a T-Mobile SIM card. As long as the networks are compatible, you should be able to use an unlocked phone anywhere in the world... again, provided you have a SIM card and are paying for service. It certainly beats buying a throwaway phone for that weekend jaunt to Bogota.

I realize now that everyone else out there who doesn't have a Nokia is going to email me, wanting know how to unlock their phone, so here are some tips:

• This only works with GSM phones. If you have a CDMA phone from Verizon, for example, you can't easily unlock it without pricey cables and software, and even if you did it wouldn't be useful anywhere but the U.S. anyway, since CDMA is not in use much outside of the States.
  
• Unlocking is most commonly done by services that specialize in it. You dial a number, punch in a code from your handset, and you get a text message with the unlock procedure in it. The charge is usually $15 to $20. You can do this online, too.
  
• To find an unlocking service (and there are many), do some web searching: "unlock treo" or "unlock lg phone." Shop around. These services aren't all exactly reputable.
• Unlocking your phone will probably void your warranty.
• Not all phones can be unlocked, even GSM phones.
  
• Remember you aren't doing anything "wrong" by unlocking your phone. Service providers don't like it, but it's not illegal. Remember, you bought your phone, and it's pretty much yours to do with as you please. So unlock away!