Found via Hacker News.
http://flashcrash.dempsky.org/
If you have even an up-to-date Flash plugin installed, it most likely will crash your browsers. It seems that this bug has been fixed in Flash 10.1 beta.
I have ClickToFlash installed, so I could actually read what this page says without having Safari crashed.
No wonder Steve Jobs won’t allow Flash on the iPhone, iPod touch and iPad.