Mouseover gallery function

If you do a search on Ebay and look at the results you'll see that some of them will have the word "Enlarge" at the bottom of a thumbnail. This allows the user to mouseover that thumbnail and have an image popup. The user can then click on the image for more information. This clears that popup and redirects the parent page to the page with the info for that item. From what I can tell this is done with a combination of javascripting and css. I need a solution that I can implement on any given website. Note that, even though Ebay is database driven, this does not need to be. I need 1) the code to accomplish this function, and 2) will probably need some help or at least documentation on implementing the code on a static webpage.