I am thinking of a polyphasic sleep schedule. what are the pros and cons i should be aware of?

Polyphasic sleep can: be beneficial for certain people depending upon your lifestyle. There is little good evidence to support the extreme forms of this practice (6 short naps throughout the 24-hour day) but there is good evidence that two 4-hour sleep cycles, or a 6-hour sleep with 2-hour daytime nap can improve alertness. Try a few different cycles for 2 weeks at a time, and keep a journal of your performance.

Not an easy choice: If you go forth, you'll have to listen to your body as not everyone does well with a polyphasic schedule. Some pro's are more "awake" time and possibly increased sleep efficiency. Some risks are possible increased fatigue, decreased sleep efficiency(I know both a pro and con), and suboptimal memory consolidation.