I came across this lovely free software when my attempts to use HTTHost + HTTPort failed as the transfer rate was too slow.
The program is called Socks via HTTP, it works with both TCP and UDP and is platform independent as it is java based.
http://lightbox.ath.cx/socks/
You use the program in combination with SocksCap or you can port forward the ports manually. The program works on the same basis as HTTHost and HTTPort by using HTTP requests, but it doesn't seem to limit the transfer rate to remain "invisible".