If you have Quicktime Pro a simple method is to use the movie to ipod export option. However in the settings (not the export settings but the command/control J video options) change the size of the movie to half of what you are working in, ie: 640x360 for half 720p. After the export change the file extension to mp4 as opposed to m4v otherwise the movie will want to be opened in iTunes.
It will automatically use the h.264 codec and play in almost any computer as long as quicktime is installed. Now you can embed your movie into a webpage. This method brought my 3.1 gig HD reel down to 22 megs and I can live with the slight artifacting I see in the beginning and end of the peice. You can check out the quality on my link if you like. Hope this helps.
http://twitchdesigns.com/reel/movie_reel.html
