Here are a couple things that I’ve been tinkering with:
A jQuery
plugin that allows you to “freeze panes” like in Excel.
It keeps the table header (or left column) visible if
the top (or left) of the table is scrolled out of view.
A
user script that cleans up Gmail’s interface, removing
redundant elements with the goal of maximising screen
real-estate.
An
explorer plugin that gives you the option of opening CSV
files in Excel without Excel trying to auto-convert all
the values in the file.