I've written a scripts for various things, but these two may also be useful to you:
- nytlink.user.js — Rewrite links to the New York Times to be links to the "print-friendly" (read: ad-free) pages. I don't click on their ads anyway so showing them to me just reduces their click-through rate.
- unembed.user.js — Add a "download" link after any embedded movie in a webpage. Especially useful on computers that don't have movie-playing plugins installed. (Arguably more useful is the bookmarklet form of unembed — with this it'll unembed only when you click the button.)
Unembed (and many more scripts) can also be found in Greasemonkey Hacks, a book from O'Reilly.Evan Martin, email@example.com