One of the things we did to make sure we all got to see everything we wanted was to print off the maps to study from the Disney Site and make a list of the priorities. We had an A list and a B list. Then we added FP in red next to the ones that have Fastpass option. It really helped to keep our priorities once we got to the park.
Wear your Anniversary pins into the parks each day. Are you going to Epcot? If so, stop in at American Adventure and hang out in the front entrance part for a few minutes wearing your pins. Wait until you are approached by a CM and see what happens.
Also at Epcot, hang out by the red phone booths if you get a chance. Every once in a while there is a caller. That can be fun!
We always like to make sure to try all transportation at least once. We take the boats one day and then the monorail, which is our favorite. Disney makes even going from place to place rather fun.
Purchase the Photopass CD ahead of time and then make sure that all members of your party get their pictures taken by the photographers at various places in each park. If there are three different couples in your party, you could split the cost of the CD. You can add multiple Photopass cards to one account - I think we had 13 different cards between the 8 people in our party. We were so glad to get them because that way everyone can be in the shots at one time. And on the photopass site you can add borders and other little embellishments. Check it out!
Get very familiar with the popular attractions and pay attention to the best times to ride. You said that you have some iphone apps? Start checking on the wait times now for all the park attractions and you will notice which ones have the longest wait times at which part of the day. Then when you get to the park, send one member of your party with all the cards to collect fastpasses for one of those attractions and then meet your party where they are waiting at another. The attractions this is most necessary for (off the top of my head) are:
MK: Space Mountain, Splash Mountain, Big Thunder Mountain Railroad
HS: Toy Story Mania
AK: Expedition Everest
There are others you can FP, but those were the ones with the longest wait when we were there.
Most important, enjoy every minute of your time there. Even the most inconsequential things seem like magical times when you are reflecting back on your trip.