The tickets are sold through a ticket lottery by the PGA – so you cannot just go and buy one. The lottery will take place sometime in the fall of this year (2007) You need to register your interest (by signing up to the PGA newsletter here). Be careful where you buy your tickets as the PGA are the only source of authorised tickets for PGA events and they protect against touts and scammers ruthlessly. They recently released the following ticket alert:

“Ticket Alert!
The PGA Ticketing Center is the exclusive agent for ticket sales to all PGA of America events. If you have purchased tickets from any other party, The PGA of America is not responsible and will not guarantee admittance to an event if you purchase tickets from unauthorized sources.
The purchaser acknowledges that tickets and badges will be for the exclusive use of the purchaser and guests. The purchaser acknowledges that any resale, redistribution or repackaging of tickets is expressly prohibited, inclusive of but not limited to including tickets in travel or hospitality packages. All sales are final.”

Naturally the other source of tickets are from the corporate sponsors and hospitality packages but you will pay over the odds for these. The upside is that they often include access to VIP areas and hospitality tents at the event where lots of wheeling and dealing is done.