Every other week, when I get paid. I deposit the check then go home and pay all the bills for the next two weeks. It usually works out that I fill up my gas tank and go grocery shopping, too.
Then I know the bills are all paid and I rest easy for two more weeks. If I have plenty of extra money (hasn't happened much lately, but I just started a new job so I anticipate a change in that shortly!) I pay bills for the next pay period. That way I never have to worry about forgetting.