If you use Firefox and have installed the Greasemonkey script add-on, you might be interested in these two scripts :
Google Maps Zoom = allows google maps to zoom in 1-2 levels deeper than normal - may take 2-3 tries to get it to display, I'm not sure exactly what it does, but it does work.
Store Notes For Every Website = excellent! Creates a small window on every domain that you type notes into - I use it to track the last article read, for example, on sites I don't visit that often. Very useful.
