The software update to Android 2.2, which began rolling out to European Desire users over the weekend, brings with it the ability to use the device as a portable WiFi hotspot: enabling you to share the Desire's connection to the Internet from any other device in range via a WiFi connection.
Setup is quick and simple, simply launch the WiFi Hotspot application from the launcher:
Enter in a name for the wireless network and specify an encryption method and password
From your PC or other device you want to connect via WiFi, search for available networks in range and select the option to connect to the Desire, entering in the password you specified earlier when prompted:
After a few moments you will be connected. The Desire will indicate how many users are connected to it via WiFi:
Advanced settings can be configured by selecting Advanced under the menu, including the ability to specify a wireless channel to use and IP address information assigned to connected wireless clients: