T-Mobile USA is now officially offering iPhone 4-compatible Micro SIM cards for use on its network. As stated on the company’s website, the offering is for customers that already have a GSM phone or iPhone they need to activate, or an unlocked GSM phone they would like to use on the T-Mobile network. The card is free with a 2 year contract, and appears to sell for $10 to those who don’t wish to sign a long-term service plan. Notably, T-Mobile…
