H264 codec

Has anybody found a way to use the h264 codec to encode movies played in a flash based web site? I've been using the Flash encoder for every thing and it works fine but when I had type to deal with: the results were awful. I tried using Sorenson when I heard the h264 codec could solve my problem. Unfortunately the video won't play-only audio. When I switched codecs to Sorenson AVC Pro I got audio and video but the quality was unacceptable. Any ideas?

Thanks in advance

Thanks, baits. I should have mentioned that I am on a Mac. Thanks for the post though. I'm thinking I may have to bite the bullet and go the CS4 route..

handbrake is open source (free) and delivers great results if you know how to use an encoder properly (i.e. aren't afraid to wait!!).