right now, software or hardware unlock for 3G is not yet available in Doha..

only thing you can do is jailbreak or activate you iphone 3G with Winpwn or Pwnage.

The only solution now in able to use any simcard is a "SIM SOLUTION" like gewey sim or turbosim or likes..
well, you need to buy this sim also..
i think iphone999 has some turbosim..because he is selling iphone 3G now with turbosim..better contact him..)

For more info on 3G iphone, check also www.applei.ph