No rooting needed. Got my T-mobile Samsung Vibrant tethered to Ubuntu today! Working like a champ! Grabbed the easytether app from the marketplace. Then went to their site to get the i386 ubuntu drivers Download EasyTether drivers Installed, ran usb debugging. Selected the T-mobile G1 network, and connected. Works Great! Speed test is giving me 1.6 mbps upstream and 2 mbps down. Where I am the 3G is horrible, but I'm moving next week to a much better coverage area and should have improved speeds there. Anyway, just wanted to say tethering is indeed possible with Linux! Very happy about that.