WHAT IT IS ?
This plugin is a Mozilla Firefox one, not really an oscommerce contribution. With this your customers will be able to add your site to the search engine box included in Firefox.
This is specific to Firefox, it doesn't work with IE...
you have a demo there :
just clic, you'll see... (if you use Firefox)
it's a lot hardcoded, I don't use any osc variables, so you can put the link wherever you want, even outside osc.