One more reason to like GMail
…and other Google products, like this experiment where you can browse around in the results entirely with your keyboard.
Why reinvent the wheel? Google decided (it seems) to use the very same keyboard shortcuts than in the (very) old but still used text editor vi. j and k to change lines, / to search, and g seems to be a combination key. In GMail you can type “g a” to go to your archives, whereas “g f” in vim will take the word around your cursor, assume it’s a file on your drive and try to open it.
As a sidenote, Google keyboard shortcuts seems to not work well on Opera, at least on Linux.