After i connected the phone to my mac using the usb cord, i selected USB tethering. I got an android phone dialog in the network preferences. I entered my sprint username/pass but nothing happened.
Using android 2.2 froyo
USB tethering is only officially supported in Android 2.2 for Windows and Linux machines. However, a number of people have gotten USB tethering to work on their OS X machines by downloading TUN drivers and OpenVPN software. See Using Android Phone as a USB Tether on Mac OS X.