A tiny company called Nullriver today released what is arguably one of the most useful iPhone applications to date: NetShare. With a tiny bit of configuring, the $10 software allows you to share your iPhone’s EDGE or 3G connection with your Mac notebook (or any computer in general). We’ve compiled an illustrated 10-step guide that we hope will simplify the configuration process and provide an overview of the software for those who may be considering it as a purchase.