From Tidal Pool Software:
Share your iPhone's internet connection with your Mac/PC. Tether allows you to quickly connect from anywhere within range of a cell data connection. It tracks your monthly data usage so you can avoid costly data overage charges. Connect your laptop using Tether and stop paying for WiFi at cafes, hotels, and airports. Tether for iPhone include support for SOCKS proxy protocol versions 4, 4a, and 5, support for HTTP/web proxy protocol, data transfer statistics for the session, month, and total to date, and quota support to track and manage the data transferred on a monthly basis.
Note: Before using or purchasing Tether, you must check with your cellular phone provider that internet tethering is included with your plan (there may be additional charges involved).