hang the cam upside down.. (so you can actually point it up more) then flip in software... when standing you want the cam actually point way up as when you're on the bike you lean forward...
chest mount is about the best for Go-pro's that I've seen. the body of the cam is too big to frame mount really, thou I did see a vid that was nice where they one of those ball joint arm mounts (there's a name I just can't think of right now) and it was mounted to the top tube and with the mount it looked just over the handlebars.. was a decent view.
under the seat is good looking back for a bit of variety..
I've never liked the helmet mount views as it's tooooo high and not only to use loose depth of field but they bounce too much and get the pinched funny fish eye like look