A cool new feature on the new Windows 7 phones coming out is the ability to login to your Xbox 360 Xbox Live account. Here are the steps to login to your Xbox Live account on your Windows 7 phone:
This guide assumes that you already have an active Xbox Live account.
1. In Start, tap Xbox Live.
2. In Games tap I already have an Xbox Live account.
3. It should prompt you to enter your Windows Live ID and password associated with your Xbox Live gamertag.
If you’re having problems with step three, check out my other guide on how to find the Windows Live ID associated with your Xbox Live gamertag.