ubuntu alternatives

as well as the select-editor command ubuntu update-alternatives lets you make your favorite browser, texteditor etc your default

find out what your default apps are currently with

$ su -
# update-alternatives --get-selections

use update-alternatives --config to interactively change a single alt

$ su -
# update-alternatives --config x-terminal-emulator

or if you have a lot of spare time you can set ALL your favorite default apps

$ su -
# update-alternatives -all