In terms of xbox 360, it means gamertag

Get Through;
To be successful at a particular venture.

To get through. Commonly used phrase in Trinidad & Tobago.

GT ~means go to

It means Grand Touring, usually the highest model of a car, can be found on many cars including the Mustang, and the Grand Am, also in italian can be translated into Gran Turismo, a famous racing game for PS2

Represents the capital of Guyana, which is Georgetown. If you are GT, you are Guyanese.

Good times.