You can now log in using your Google account, in addition to the Facebook and Twitter login already announced. To connect your existing CougarBoard account to your Google account, just click on your username in the top right, and select "Connect to Google+" from the menu.
If you don't already have a CougarBoard account, you can create one by clicking "Login with Google+". After accepting the connection to Google+, you'll be asked to create a CougarBoard username.
Also, if you weren't able to connect using Twitter, that should be fixed now.