Miscellaneous All these days lots of type of wireless communication, digital gadgets is already on the big market. It is really amazing, all kinds and different styles and colors of cell phone with a high technology adaptation at top brands of gsm cell phones. GSM cell phones are designed to work with any service provider. In theory, all you need to do is swap the SIM account card in the phone. But some service providers 'lock' the phone they sell you. Many mobile network operators lock a mobile phone to their network, ensuring you can't just up and leave them whenever you feel like it. They do this by locking your phone's SIM to the phone itself, so no other SIM will work in it. But what if you do want to switch networks? What if you want to leave your old contract and go to a shiny new (and cheaper!) operator, or just switch SIMs to use a local operator's network when you travel abroad? Business - List of business/finance/loan/mortgage resources more 1 2 3 4 5 Computers - List of computer hardware/software/peripheral resources more 1 2 3 4 5 Internet - List of webhosting/webdesign/internet marketing resources more 1 2 3 4 5 Software - List of software resources more 1 2 3 4 5 Web Design - List of web design/development resources more 1 2 3 4 5 Web Hosting - List of web hosting resources more 1 2 3 4 5 Web Promotion - List of search engine optimization/internet marketing resources more 1 2 3 4 5 Web Resources - List of other web resources more 1 2 3 4 5 Recreation - List of travel/hotel/cruise resources more 1 2 3 4 5 Casino - List of online gambling/poker/blackjack/roulette resources more 1 2 3 4 5 Health - List of online pharmacy/hospital/health resources more 1 2 3 4 5 Shopping - List of online shopping/gift resources more 1 2 3 4 5 Miscellaneous - List of all other resources not stated above more 1 2 3 4 5   When originally manufactured, all GSM cell phones are unlocked. That is, they can be used with any SIM from any cellphone service provider - always assuming, of course, that the cellphone service provider has compatible GSM service on the same frequency bands that the phone can operate on. Most cell phone service providers electronically 'lock' the phone so that it can only be used with their service. There are obvious reasons why they choose to do this - in particular, to force you to pay what are usually very high roaming charges when you take your phone out of their network and use it elsewhere in the world.