I believe Baloo is not correct about the Plus options expiring. Here is info from Deb Will's site:
"Good news! No, you don't have to use the Plus options during your six "major park" days--they are good forever, just like unused days on your hopper would be. You can use them at the end of your trip, the middle of your trip, beginning of your trip, or save them until your next visit if you wish. According to All Ears Net's Ticket Expert Guy:
Park Hopper Plus Pass - Provides unlimited admission for the number of days purchased (5, 6 or 7) to the Magic Kingdom Park, Epcot, Disney-MGM Studios, and Disney's Animal Kingdom Theme Park. Freedom to go from theme park to theme park on the same day PLUS a choice of visits called Plus admissions (2, 3 or 4 depending on what pass you got) to the following: Blizzard Beach, Typhoon Lagoon, Pleasure Island, and Disney's Wide World of Sports Complex.
Visits with multi-day passes do not need to be consecutive and unused days and the unused Plus visits never expire. You cannot park hop at the minor parks when using your Plus options. Each admission to a minor park counts as one Plus option."
DisneyWorld.com just states "Unused days never expire." I would think they would explain that the Plus options expire if they did.
Hope this is correct as I plan to save 2-3 pluses from our 7 day tickets for our next trip, whenever that may be.
Cathy