The official Sidelines Group is up for the ESPN Tournament Challenge. Enter as many brackets as you'd like (the more the better!) and there is no password.
There is also a Sidelines group for ESPN College Hoops Pick'em, a game in which you get points for selecting the winning teams each round. Again, no password needed.
If you have a group or would like to start a Sidelines group for another site, put the info in the comments!