You’re as amazed as I’m how short this article is as I’m. I looked through the Internet before I tried it myself and did a look at articles like this. Almost all wrote how complicated that is (e.g. a HTC Software for Windows that works or not) or that you need a software like PDAnet. Thats absolutely not true for the HTC Desire with an Ubuntu 10.04 notebook/netbook. I just connected both via the shipped USB cable and selected on the Desire to share the Internet connection. And guess what happend the Network Manager told me that I’m connected to the network. I couldn’t believe it so I flipped to my shell windows and did a ping. And yes, I was connected. I really don’t understand the problem now the people have. Wrong OS on the notebook? 
Some guys in the Linux/Open Source world talked with each other and made it just works out of the box – no special applications or drivers – it just worked. Big THX guys!!! I really love my Ubuntu and Android!