Review for CustomizeGoogle by chrisWhite
Rated 5 out of 5 stars
Can't live without this extension. I use it to force secure connections, add extra search engines, position counter and counters and even filter some loathed sites (Experts Exchange anyone?), etc.
You could do this with a bunch of Greasemonkey scripts, but CustomizeGoogle is really powerful as a collection of great features. Highly recommended!
To create your own collections, you must have a Mozilla Add-ons account.