Please pardon me if this has been suggested before or if it already exists.
I am in love with Wikipedia. What I, as a fairly new Wikipedia user, would find terribly helpful would be a Wikipedia Lookup Button for my browser similar to what Merriam Webster has:
1) I'm reading something on the web that I would like to know more about 2) I highlight the phrase or word that I want to look up in Wikipedia 3) I press the Wikipedia browser button 4) Boom! I'm taken right to the correct Wikipedia page