ClockworkMod Tether, is in its very early stages, though, and the current APK is set to time-bomb on Jan. 7. However, Dutta will continue to release updates.
This isn't the first non-root tethering app for Android; PDANet comes to mind. Just as with PDANet, a desktop component to the app is required. As Dutta notes, without rooting your Android phone, a desktop app is needed.
Install the desktop application from the link above, and if you don't have the proper drivers on your PC yet, you'll be prompted to install them. Most of the time the drivers will install directly from your phone; sometimes, you'll have to look for them on the Web.
Once you run the desktop application and plug in your Android smartphone, the tethering app will be installed on the phone (USB debugging needs to be enabled on the phone). Currently the app only works over USB, but Dutta is working on Bluetooth.
Dutta gets around carrier detection of unauthorized (meaning, you're not paying for a tethering plan) by having ClockworkMod Tether work as a proxy, and not as with network address translation (NAT) like other tether solutions use.
Carriers could use the user-agent string from the browser to try to detect it, but we doubt that: there are quite a few browsers on Android that spoof desktop user-agent strings. On the other hand, they will probably notice if you are playing a lot of WoW on your smartphone.