Tethering HTC Desire
USB
To tether using the USB cable on Debian 5.0 (Etch), install the dhcpcd package.
# aptitude install dhcpcd
Connect the HTC Desire to the PC via the supplied USB cable and select the "Internet Sharing" option
Use /sbin/ifconfig to check that a usb device has been created, usually usb0
Run dhcpcd to create the network connection
# dhcpd usb0
The allocated IP address should be visibile with /sbin/ifconfig
Trouble-Shooting
Check the routing table:
# /sbin/route -n
Check that there aren't other name servers in /etc/resolv.conf
# vi /etc/resolv.conf