http://andre.arko.net/2010/04/04/ipad-internet-via-iphone-without-jailbreaking/
Create a file named socks.pac, and put this in it:
function FindProxyForURL(url, host) { return "SOCKS 10.0.0.1:8888"; }Choose "Auto", and type in the URL of the file you are sharing from the iPhone. For me, that was "http://10.0.0.1/socks.pac".
めも