Most of new sites devlopped by us (http://www.acolyte.ws) use your prettyPhoto plugin.... We did modified it a bit to be a complete replacement to the prototype / scriptaculous plugin called lightview to get rid of the prototype library (100kb) for our visitor, thank you stephane!
Whew. Finally got it working across all browsers - not prettyphoto's fault - Note: if you add extra parameters, leave off the last comma before the brackets.
Here you can you see the glory: www.airmasters.net
Loads up a jpeg and a youtube video. I use it for loading pdfs in an iframe elsewhere on the site, works great.
I've seen a few pages using the addthis button. I'm using pretty photo in word-press. can you guys please share the coding if you are using word-press?