Afraid not. Unlocked just means you can use whatever GSM carrier you wish. Carrier-dependent features (MMS, tethering) are controlled by IPCC files (known as 'C

Afraid not. Unlocked just means you can use whatever GSM carrier you wish. Carrier-dependent features (MMS, tethering) are controlled by IPCC files (known as 'Carrier Updates') which are downloaded depending on the carrier you are using. In the old days (3.0 and below) you could get access to features unsupported by AT&T (MMS, tethering..) by modifying a carrier file and applying it to your phone via iTunes, no jailbreak required. As of 3.1 however these files are now signed to prevent tampering.