What is unlocked for a phone?

An unlocked cell phone is one that is not branded with any particular company, such as Suncom, T-mobile, or Cingular. Most unlocked cell phones are GSM which means that they work on the above listed companies or basically any company that requires a SIM card. The advantage to unlocked phones is that they benefit those who travel overseas as you can purchase overseas cell phone plans and use the SIM cards they provide. The cost of unlocking a cell phone usually ranges from 20 to 40 depending upon who you get to do it. You can also find unlocking tools on the internet but not all are reliable. The best place to find really great unlocked gsm phones is on www.unlockphones.biz I hope this helps :)