Today is Pac-Man's 30th "birthday" and in honor of this Google's homepage has an interactive thing on it. Hit insert coin and you can play pac-man to your hearts content on the google homepage.
Unfortunately, this is causing a buggy problem for firefox users with Cool Previews and Cooliris add on's causing the pac-man sound to play. Over. And Over. AND OVER. Disable these (and recommended any other "preview page" type add on's) restart firefox, and it solves the issue.
Thought I had some weird virus till I found this out.