Error establishing a database connection

Hey folks-
I've been having some minor problems with my site, but came back after a week of being away and my site is no longer functioning. My url is tutuology dot com. The message I receive is: Error establishing a database connection. That's it - nothing else appears.

What has happened? Prior to wpmu, I hosted my wordpress site with Fatcow. My billing agreement with them was 1 year, (which just expired), However, I have been using psek since the migration.

Just thought I'd add that bit in there in case it has any significance to this database error problem.
Any quick feedback would be much appreciated.
Thanks,
Kel