You don't need to do any of this or need root access, i've had 3 android phones (hero, desire, galaxy SII) and I've never had to do any of this. Just plug it in and select USB tethering and it is recognised by ubuntu as an ethernet adapter.
http://insidesprintnow.files.wordpress.com/2009/09/hero_gsg....
Lol, had to look it up for my own piece of mind, i was sure i could remember tethering on my old Hero back in the day.