When you tether with your Android-powered smartphone, you can connect to the Internet on your computer from any location covered by your cellphone service provider's network. Tethering allows your phone to act as a modem for the computer. Tethering applications such as Tether for Android allow you to set up tethering without the need to root your phone. Before tethering, check with your cellphone service provider to determine how much data you are allowed to use without incurring data charges. Excessive use of the Android phone as a modem can cause you to exceed your allotted data.
Search the Android Market on your phone for a tethering application. Applications such as EasyTether and PdaNet are available to download for free. Download the application from the Market. Installation begins immediately after the download. When installation finishes, an icon for the tethering app is placed on the Android's expanded home screen. Open a Web browser on the computer and access the site specified in the tethering application's description in the Market. Download and install the USB drivers needed to tether from the site. When installation is finished, an icon for the tethering application is placed on the computer's desktop. Tap "Settings" on your Android phone, then tap "Applications." Tap "Development" and enable "USB Debugging." When the field turns green, it is enabled. Connect the phone to the computer with its USB cable. Launch the tethering application on the phone. Launch the application on the computer. Click the option to connect to the Internet in the home screen. When the connection is established, confirmation is displayed in the status window.
Android 101: Tethering http://www.androidcentral.com/android-internet-tether EasyTether
shares your Android smartphone connection with your PC. http://www.mobile-stream.com/easytether/android.html