WordNet (r) 3.0 (2006):

lickety split
    adv 1: without delay; "she tackled the job lickety-split" [syn:
           lickety split, lickety cut]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "lickety split":
   amain, apace, at flank speed, double-quick, expeditiously, fast,
   hand over fist, hand over hand, hastily, hell for leather,
   hell-bent, hell-bent for election, in double time,
   in double-quick time, in high, in high gear, in seven-league boots,
   lickety-cut, on the double, post, posthaste, promptly, quick,
   quickly, rapidly, snappily, speedily, swiftly, trippingly,
   under forced draft, whip and spur, with all haste,
   with giant strides, with rapid strides, with speed