This is an example of how to include two different qualities of one video. Here you can switch between the two videos »nice-flowers-hd.mov« and »nice-flowers-sd.mov«. These two videos aren't very big to keep this .zip file small. It shouln't be a problem to include a video with 720p, for example. Try different sizes to find your perfect setup.
This video really needs to be changed (especially the colours of the controls)!
See the souce-code of this site if you want to know how the movie was embedded.