Firefox Add-ons

I've got the No-Script add on which is really useful for blocking questionable scripted applications. It can be a tad annoying to get around, but it's benefits outweigh it's negative aspects. I also have the dictionary add on (completely useless), and an add on which allows you to download streaming videos and save them on your computer. I really like that add-on, especially when I want to have YouTube videos saved for when I go places without internet. I don't think there's such a thing as "too-many applications", but there is such a thing as "too many useless applications." They take up space and they do nothing for you.