Well, after complaining about Colorado wind power so much I have to give them credit and point out that Xcel Energy is now accepting more subscribers into Windsource.

Bonus #1: They have an Online Signup form though it doesn't do a very good job of recognizing and remembering where you live.

Bonus #2: They even have a fancy new logo to show off that they are 100% wind power compliant:

From Green E.org.