In Two Shakes Meaning

(dated, idiomatic) Very quickly; without delay.

Example: 1906, Edith Nesbit, The Railway Children, ch. 2,
  She tried to get the case open. . . . "I wish Father was here," said Phyllis; "he'd get it open in two shakes."
1910, William MacLeod Raine, A Texas Ranger, ch. 5,
  I'll have coffee ready in two shakes of a cow's tail.
1922, Agatha Christie', The Secret Adversary, ch. 19,
  I'll be back in two shakes of a dog's tail.
1922, P. G. Wodehouse, Right Ho, Jeeves, ch. 16,
  In two shakes of a duck's tail Gussie, with all that lapping about inside him, will be distributing the prizes at Market Snodsbury Grammar School .
2005, Adrian Higgins, "And All the Trimmings," Washington Post, 15 Dec, p. H01,
  Skilled sheep shearers can get the wool off a ewe in two shakes of a lamb's tail.