Ok, there may be a plugin that already exists that does exactly what I'm looking for, but I can't find it...
In my posts, I often link to IMDB pages when referring to a movie. So, I highlight the movie title, click the Create Hyperlink button in the toolbar, and paste in the IMDB link, that is after I have looked up the link in another Firefox tab.
What if a NEW button was added to the toolbar? So, you highlight the movie title in your editor, click this button, and it searches IMDB for that title. If there's multiple options, you get a popup to select the correct one. Bang, the link is there.. no secondary browser window is needed.
Anything similar around?