Welcome to my very own "P.K."...

Named after the lead character in my favorite book - "The Power of One" by Bryce Courtnay - and with a double entendre to boot. It can mean Piccaninny* Kaya (Little Room/Out House/Toilet) or Piss (Pee/Urine/Pissed = drunk) Koop (Head) in essence - Drunk Head.

The “P.K.”:
Make a “Malawi Shandy”***
Add One Table spoon (0.5 Ounce) of Roses Lime Juice
Add 1 Shot (2 Ounces) of Vodka
Add 3 More Dashes of Angostura bitters
DO NOT SHAKE or STIR – Let it settle as you sip.

The Actual Cocktail is simple and an alcoholic variation on the virgin sundowner “Malawi Shandy”
***Version 1: (as used in Malawi, central Africa) **
Use a tall glass, half to 3/4 filled wich ice
Add half a glass of [bottled] lemonade to half a glass of [bottled] ginger ale
Add a dash of Angostura bitters and a slice of lemon and sitr.

***Version 2: (as described on a british cocktail website) **
Use a tall glass, half to 3/4 filled wich ice
Add half a glass of soda water to half a glass of ginger ale
Add a dash of Angostura bitters and a slice of lemon and stir.

CHEERS!

*PICCANINNY, or Pickaninny, a word applied originally by the negroes of the West Indies to their babies. It is adapted either from Span, pequeño, small, or Port, pequenino, very small. The word spread with the slave trade to America, and has since been adopted in Australia and in South Africa. - 1911 Encyclopædia Britannica/Piccaninny
** http://wiki.answers.com/Q/How_do_you_make_a_rock_shandy#ixzz1khlBk4b9