Or add the power control widget to one of your home screens. The widget allows for Wi-fi, blutooth, GPS, Sync, to be turned on and off easily, but finally allows the screen's brightness to be easily adjusted with one button press from the current brightness to full brightness. This makes the screen decently viewable outside with bright sunlight, to simple presses of the same button and your back to the screen setting you were at.
Seems like a lot of the HTC phones have sunlight issues. Not sure if it's because of the Gorilla Glass?