It is rare you will see my posting about firefox plugins anywhere on the web, but I've just found one that is absolute awesome.

http://www.piclens.com/site/firefox/win/ or
https://addons.mozilla.org/en-US/firefox/addon/5579

Depending on what you prefer. Install it, goto google images (also works on Flickr, Smugmug, DeviantArt, Photobucket, Picasa, Facebook, MySpace, Bebo, Hi5, Friendster
Image search on Google, Yahoo, Ask, Live, and AOL)

Hover over a picture (try google images first) and press the play button and be amazed.

This will only work on firefox, so tough luck internet explorer users!

EDIT: There might be an IE version, but it's not as good!

"IE users not invited"