A lesser-known Firefox extension put out by Google a few weeks ago is the Blogger Web Comments for Firefox. I installed it a few weeks ago and I’ve got to say, I really enjoy using it.
It works like this: when you’re on any web page, a small icon in the status bar spins around and tells you if other bloggers have commented about the page you’re looking it. If they have, it presents an in-line summary of the entries right there on the page in the bottom-right corner. Nice stuff.