Transparent page overlay?

[kirupafalcon]

can anyone point me to a tutorial or script that creates the following cool effect

http://www.motorcars-intl.com/veh_detail.aspx?stockno=M-3962&title=2001%20Lamborghini%20Diablo%206.0%20VT%20Coupe&stocknoid=295

click on any of the the thumb nail car pictures.

Thanks