Firefox Extension, MacWorld Conference

So, for those of us who work in a quieter office, I think there's a Firefox extension I want. Before any web page plays any sound or music, I want a warning tone. So if someone links me to a site that has a song playing in the background, I want a four count beep (beep beep beep beep) and then whatever the actual sound is.

That way, I at least have a second to turn down my speakers to a reasonable volume after I've been tricked into clicking on a link to a Rick Astley video.

Anyone know if something like that exists for Firefox? Safari?

In other news, MacWorld is today. Rumor mill suggests a 16 GB iPhone, 1.1.3 software release, Open SDK release, but still no GPS. On the laptop front, a thinner/lighter model, possibly with an all solid-state drive. Also, wireless everything; hard drive with integrated wireless, or ubiquitous wireless networking in a laptop using WiMax, EDGE, or EVDO. iTunes might become a Netflix-like video rental. Should be interesting. 9 AM PST, no live webcast this year.