What the f*** is the big fuss about this unnecessary plug-in or something? This is Firefox, you can already add any search-box you encounter in the internets.
I was reading all the reviews, and didn't see any different thing it does than to let you use the search-box of IMDb through your Firefox search-box.
Well guess what, there's an extension called Add to Search Bar, and I use that for every site whose search-box I use frequently.
You just right-click in the box and go "Add to Search Bar.."
I, for example, just type "d" and type whatever I'm gonna search after a space.
This is Firefox we're talkin about here people, you don't need an extra add-on for every search-box you use often and wanna add.