I am looking for a methodology for categorizing keywords I.e. I want to put in Baseball and get out Sports & Outdoors. 
 A: Try WordNet.
The relation beween Baseball and Sports is called hypernym. 
Here is a snippet out of WordNet's baseball hypernym hierarchy:

S: (n) baseball, baseball game, ball (a ball game played with a bat
  and ball between two teams of nine players; teams take turns at bat
  trying to score runs) "he played baseball in high school"; "there was
  a baseball game on every empty lot"; "there was a desire for National
  League ball in the area"; "play ball!" direct hyponym / full hyponym
  domain term category direct hypernym / inherited hypernym / sister
  term S: (n) ball game, ballgame (a field game played with a ball
  (especially baseball)) S: (n) field game (an outdoor game played on a
  field of specified dimensions) S: (n) outdoor game (an athletic game
  that is played outdoors) S: (n) athletic game (a game involving
  athletic activity) S: (n) sport, athletics (an active diversion
  requiring physical exertion and competition) S: (n) diversion,
  recreation (an activity that diverts or amuses or stimulates) "scuba
  diving is provided as a diversion for tourists"; "for recreation he
  wrote poetry and solved crossword puzzles"; "drug abuse is often
  regarded as a form of recreation" S: (n) activity (any specific
  behavior) "they avoided all recreational activity" S: (n) act, deed,
  human action, human activity (something that people do or cause to
  happen) S: (n) event (something that happens at a given place and
  time) S: (n) psychological feature (a feature of the mental life of a
  living organism) S: (n) abstraction, abstract entity (a  ...

