NetShare is one app we never thought would make it onto the official iPhone App Store. All it does is set up a SOCKS5 proxy for you to get your laptop/computer online through use of the 3G/EDGE connection. Does it work? Yes. Yes it does, much to our surprise. EDGE works just fine, although Mahoney says it's slow as balls. 3G impressions in a sec. Be careful of how much bandwidth you're using, since your provider probably makes a frowny face at you using their network to power your laptop, however "unlimited" your plan may be. [NetShare - Thanks Matthew and Ryan!]
Update: Having problems setting it up on my iPhone 3G. I follow the instructions and the phone seems to "connect", but that's about it. No connections shown in the NetShare app, and nothing goes through.
Update 2: Now we're getting the message that it's not available in the US store. Sucks.