EDIT 2: As of now (unless you already had downloaded it) it looks like NullRiver is still trying to get NetShare back up.
This app is simply a MUST for people who have bought the iPhone 3G and the complementary 3G data plan that comes with it ($30). If you are paying $30 for unlimited data (actually it is technically 5GB per month) you might as well be able to share that 3G internet connection with your laptop!
NetShare, available for $9.99 at the App Store delivers just that.
Only available via direct link:
EDIT: NetShare has been removed w/o explanation from Apple!!! Oh-no’s.