<p>I'd like to automatically login to VSS when I open it, and skip the login prompt altogether.  Is this possible?</p>

Answering my own question:
1 - Right-click My Computer, click Properties
2 - Click "Advanced" -> "Environment Variables"
3 - Under User variables for , click "New".
4 - Variable name = "SSUSER", Variable Value = < your VSS username >
5 - Repeat steps 3 & 4 for "SSPWD" and < your VSS password >