In reference to the Gravatar icons in the post. You guys are always asking for the 140x140 sized icons and they are then re-sized to 20x20 or 30x30. You have the ability to ask for the gravatar icons in your specified format, which will save a lot of bandwidth.

https://secure.gravatar.com/avatar/e7e8748f7897c2d9a3da0afe4... 32kb

vs

https://secure.gravatar.com/avatar/e7e8748f7897c2d9a3da0afe4... 2.71kb

Making this one change alone will make a huge difference.