Pop-up window with faded background

I've seen more and more sites using this....When a pop-up off a link is created the new window appears and then main site that is now in the background is faded or has a colored trasparent look over it.

Example would be a photo album link that creates a new window and then has pictures to scroll through. The main site that is in the background becomes faded.

Any idea how this is accomplished or even what it is called?

Thanks

I believe you're referring to Lightbox, get it here : http://www.lokeshdhakar.com/projects/lightbox2/

Really great for good looking galleries.

Not exactly although it is a cool way to go thorugh a photo album.

I will try and locate an exact example on the web.

The new window is usually smaller, thus the main browser window can still be seen in the background and is faded.

Correction. That is exactly correct.

Thank you.