However, if you are looking to buy tickets when you get down there instead of beforehand, MapleLeaf Tickets has their office right outside the World. You can find their information on Deb's site (the BEST WDW Fan site, IMO):
Fair warning...prepare to lose at least several hours of your life in that site...she has such great information about EVERYTHING that you will read until your eyes fall out of your head! If you need just the ticket information, you can find that quickly though...very well organized site.