From Spread Firefox,
Thanks to the support of the always amazing Mozilla community, we now hold a Guinness World Record for the most software downloaded in 24 hours. From 18:16 UTC on June 17, 2008 to 18:16 UTC on June 18, 2008, 8,002,530 people downloaded Firefox 3 and are now enjoying a safer, smarter and better Web.
I cannot even imagine how happy the guys at Mozilla would be! They wanted the world record, now they have earned it! I got my self a certificate too!