Need a bit more information.
Is it happening on every site you visit? It sounds like a rogue plug-in (effectively an infection of the browser) that places contextual text ads (similar to the ones vibrant media and intellitext have on some sites) in the pages using JavaScript.
It might be a search-bar add-on that you've installed (either on purpose or inadvertently) that is doing this, and if that's the case it can be easy to solve. But if it's something that has effectively infected Firefox it could be harder to deal with.
First thing would be to disable your add-ons and see if the links are still there.
I disabled java console and they've gone :-)
Will I miss it (java console that is)