Most cell phones that are purchased directly from cell phone providers are locked, which means that the phone can only be used through the provider's network. Unlocked cell phones can be used on any cell phone network. Unlocking a cell phone should be done by individuals with experience. The best place to buy cheap cell phones that are unlocked is at online auction sites like Ebay. A community site, such as Craigslist, is another good place to buy cheap unlocked cell phones.