I don’t have Quicktime installed on my Linux machine, and unless you have crossover, you probably don’t either. There’s always mplayerplug-in, but I’ve never had good luck with that. Finally inspired by Mozilla bug 255704, I’ve made a bookmarklet that converts every OBJECT tag on a page into a link to the source. You can then right click and download it.
Just drag this link to your bookmark toolbar: Objects to links
Note: right now this doesn’t work at the most useful location: Apple Trailers. They use some funky quicktime forwarding stuff. I’m working on a solution.