PDQ
after
amain
anon
apace
as soon as
at once
away
by forced marches
closely
contiguously
cursorily
decisively
directly
expeditiously
feverishly
forthwith
furiously
hand over fist
hastily
helter-skelter
hotfoot
hurriedly
hurry-scurry
in a jiffy
in a second
in a wink
in no time
in passing
instantaneously
instanter
instantly
intimately
just now
just then
momentaneously
momentarily
momently
now
on the dot
on the instant
on the nail
on the run
on the spot
pell-mell
presently
pretty damned quick