If you use, please leave a note so others don't try.  Enjoy.

Your code is: T6C4W-DTMYP-PVK3C-YBCBJ-GTMM8

To activate your Xbox LIVE Gold 48-hour free trial follow the steps below.  Go to step 4 if you already have an Xbox LIVE membership.
1. Connect Xbox 360 TM to a broadband internet connection.
2. Press the Xbox(R) Guide button, and in the Xbox 360 Dashboard, select Xbox LIVE.
3. Follow the on-screen instructions to create your Xbox LIVE account.
4. Sign in to Xbox LIVE from Xbox 360 Dashboard.
5. Select Xbox LIVE Marketplace.
6. Select Redeem Prepaid Card or Promotional Code when prompted, enter your code, and enjoy