Search and Replace is the greatest plugin ever — in 30 minutes I was able to do what would’ve taken forever manually: edit my 1100-some posts and pages through MySQL (like changing <b> tags to <strong>, deleting target="_blank" from links, etc.).

Firefox’s feed reader extension, Sage, is also pretty cool. All you do is add a RSS or Atom URL to your “Sage Feeds” bookmarks folder, and when you open Sage, they’ll be there for your reading pleasure.