HTC Desire User Manual page 243

Finding your location
1.
Press HOME
2. On the Google Maps screen, press MENU and then tap My
Location. Your location is shown on the map as a blinking blue dot.
Moving on the map
Swipe your finger on the screen or the optical joystick to view other
areas of the map.
Zooming in or out of a map
Tap to zoom in; tap
, and then tap
to zoom out.
Maps and location 
> Maps.