Of all the applications you can upload to the iPhone thanks to the Jailbreak and iPhoneInterface hacks, a SOCKS proxy daemon is perhaps the most useful. It’s also the best way to make full use of an unlimited data plan.
Recent developments have allowed iPhone hackers to compile background applications for the iPhone – among the most interesting so far is srelay, a SOCKS proxy server.
srelay running on your iPhone opens up a very exciting possibility – you can use your iPhone’s EDGE connection with a laptop or other Wifi-enabled device.
This is about as essential as it gets for laptop users who regularly travel outside the range of reliable WiFi. When this is activated, you’ll be able to browse the web on your laptop just about anywhere you can get a cell signal. Your laptop will connect to the iPhone over an adhoc WiFi network, and the SOCKS proxy will happly funnel your web requests over the iPhone’s EDGE data connection.
I should also mention that this sort of functionality is a typical feature for just about every other phone on the market — I’ve been doing this with my GPRS Windows Mobile phone for years — so it’s nice to see the iPhone finally get with the program.
Tether your iPhone: EDGE internet on your laptop – Link