I have seen this on a few sites, it's basically something thats always on the same position of the page regardless of where you are. Alienware has one on their configure page for the current price. I've searched google but can't find anything. If anyone could point me in the right direction that would be great.
I really hate buttons and menus like this. (the logo in the example link is a little more tolerable) I get away from these pages as quickly as I can. It is much worse than any blinking/color changing text thing.
If the floating menu, button, etc. didn't initially scroll with the page, it might be okay. But the way they normally work is very distracting. I usually use IE as my browser - maybe they behave better in FireFox.