When I edit multiple files I oftentimes want to go back and forth between the last edited files. I know about :bn(ext) and :bp(revious) to switch between b
Check out the lustyjuggler buffer plugin. It's awesome for this. It keeps the buffers in last used order and maps them to the home row keys so you can very quickly go back/forth between them.
http://www.vim.org/scripts/script.php?script_id=2050
You can see it demoed toward the end of my most recent vim screencast were I go over buffers: http://lococast.net/archives/185