This documentation is relevant to WMWifiRouter version 1.20 and newer, and has been last updated to reflect the changes in version 1.25.
This connection profile shares your cellular data connection over USB. This connection profile uses the least power, but has a fair number of requirements. The most obvious one being that it requires an USB cable.
There is also the matter of compatibility and required software running on the computer you connect to. The required software is available for Windows XP, Windows Vista, and many flavors of Linux. The key piece of the required software is the RNDIS driver, which is used to communicate with the mobile device over USB.
Windows XP
On Windows XP you will need ActiveSync version 4.5 or newer. Some versions of Windows XP come with this software pre-installed, though most do not. This software is often included on the CD/DVD that came with your mobile device. If not, you can download it from the Microsoft website.
Windows Vista
On Windows Vista you will need Windows Mobile Device Center. As with ActiveSync, this software is often included on the CD/DVD that came with your mobile device, though you can also download it from the Microsoft website.
Linux
On Linux you will need the usb-rndis-lite package. It is available in different versions and package formats from various sources - it may even come with the distro you are using. Consult your distro's documentation or website on how and where to download and install this package.