For those with a iPhone 3G or 3GS with the latest version of firmware (and baseband ) and want to unlock the phone, ie you can use cards < > SIM of any operator, George Hotz aka Geohot has released Blacksn0w , a downloadable software through Cydia (for which they need to do jailbreak that is very easy by Blackra1n ).
It’s free, do not pay anyone and the process is fairly simple.
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