[hackbinary]

up arrow

ctrl-a (readline command for beginning of line)

type "sudo"

Also, ctrl-w is really useful. Heck, learning the readline editing keyboard in general is really useful.

[al_form2000]

        $ foo bar baz<cr>
        ^P^A<esc>u
        $ FOO bar baz<cr>

That's three keystrokes less - even for the history (!!) version. :-)

[apexalpha]

sudo !!