Not content to provide us with ClockworkMod Recovery and other fine hacks, Koush just made a free USB tethering app available for Android aptly called ClockworkMod Tether Alpha. While it's not the first app to bypass paid tethering plans, it supports unrooted phones and works with Linux, Mac and Windows computers. Just enable USB debugging on your phone, download the appropriate installer for your desktop OS of choice, then connect both devices via USB and you're all set. The installation process creates a virtual network adapter on your computer and pushes a matching APK to your phone. A proxy is used to avoid detection by the carriers.
We tested the app on a late-model MacBook Air running OS X Lion and an AT&T-branded Samsung Captivate Glide -- along with a couple other handsets -- without much success (as documented in the screenshot above). Then again, based on the discussions following Koush's Google+ post (source link below), the app appears to work for many folks and continues being tweaked on an hourly basis. Clearly your mileage will vary, but let us know in the comments how it's working out if you've installed the app.