I've just accquired a Trium Geo @ mobile phone, it works fine on o2 (Displays BT CELLNET), though I would like to use it on T-Mobile but the handset needs unlocking.

I do not have the sim card that came with the handset, so who do I contact about unlocking it? BT CELLNET (o2) or Mitsubishi?

Cheers

the local market stall should help you out

Dan