I don't mind the chest mount harness. If you have it done up tight enough it shouldn't bounce too much. I also set it up in upside down mode so that you can angle the camera far enough forward to ensure the right angle while standing up on the bike.
I find helmet mounting doesn't do much justice for the video, unless it is side mounted with a bit of the helmet in the shot. Mounting to the frame always works well. Handlebars is no good, as if you do a lot of bar work the video is swinging from side to side and is very difficult to watch. I have made a couple of custom mounts to try and find different angles. On top of the rear brake caliper looks pretty awesome.
Checkout the photos on flickr. There is a pile of mounting photos and GoPro photos from the bikes.
http://www.flickr.com/photos/earthwindnwater/sets/72157632057875283/
Here are a couple of videos
[video=youtube;ldC56vAqlkc]http://www.youtube.com/watch?v=ldC56vAqlkc[/video]