Not really an exploit though it could help in clearing to bosses faster. On things that have CD's of 30 seconds or greater you can reset them rather quickly. This is prolly best done in public games w/ friends or do like I do. When MF farming inferno in act 4.
Pop your CDs and once my highest CD is down (Cheat death 90 seconds) then simply
Leave game (10 seconds)
Resume game
All CDs ready for another go at Leah ghost or Jar farming in act 4 inferno.