I was bashing away at the web as you do, and I spotted an interesting feature in Firefox and tables. You are able to select individual (and multiple) cells from a table by pressing the CTRL (or Apple key on OS X) as you hit a table cell, go ahead and try below (if you are watching this in Glorious Firefox-Vision)

Select Me	Not me	Select Me
Not me	Select Me	Not me
Select Me	Not me	Select Me
Select Me	Not me	Select Me

Any other features that people have come across...post them here!