For the actual prizes that are associated with the Year of a Million Dreams (Dream Fastpasses, Dream Ears, Dream Pin Lanyards, the trips, the castle stay, etc...) there is not a way to get "picked" it is completely random...
There is a computer system that is run by Creata (an outside company), it randomly prints out time, place and prize. The head manager of the project gets these, puts them in an envelope and seals the envelope with the Park name, time to open the envelope and the date printed on the outside. The Dream Squad gets the prizes delivered to them in black bags with the envelope zip tied to it, if it is the Dream Fastpass, Dream Ears or the Dream Lanyard. They are able to open the envelope about 30 minutes prior to the actually delivery time of the prize. The letter inside will say something like Issue 100 Dream Ears at 1:30pm at the entrance turnstile at Dumbo. At exactlly 1:30pm (yes they have synchronized watches) they will be at the turnstiles of Dumbo and the next 100 people to go through them will be issued the prize.
If it is a big prize, the night in the castle, a trip around the world, etc it is a little different. They will get the envelope only about 5 minutes before the delivery time and the information will be VERY specific. It will say something like Issue Cinderella Castle stay at Rock N Roller Coaster at 2:23pm to the guest in row 4 left seat. The next car to enter the unload on or after 2:23pm the guest in row 4 left seat is the winner, if there is not someone in that seat at that time, they will send the prize back into the computer to be re-issued at a different location and time.
It is a completely random process and being audited by Ernst & Young (outside company) to make sure that it remains that way.
Also keep in mind that the Dream Squad has two roles, the ones issuing the prizes will have on khaki pants, a blue button up shirt and a white vest with the logo on it. They are very elusive and will stay in backstage areas as much as possible, just popping in to issue prizes and then vanishing again. The other role is super greeter, when they are in this role they will have on the khaki pants, blue button up shirt but they will NOT have the vest on. They will be carrying a black messenger bag with the logo on it. They do not have prizes when they are in this role, they are simply mixing and mingling, making sure your having a good stay, answering questions and just being visible for assistance. Many people confuse them with the prize team and think they "almost won" but they did not... the prizes have very specific locations and deliver times, they can not be altered...
The prizes are being issues at Magic Kingdom, Epcot, Animal Kingdom, MGM Studios, Typhoon lagoon, Blizzard Beach and Downtown Disney.
The castle stay is given out nightly but can be given out at any of the distribution locations, so it will not necessarily be a guest at MK that wins, you could win this at any of the parks, water parks or downtown disney.
Here is the info about postcards from the official rules:
eligible participants can enter without being present in a Disney Property by writing their full name, complete mailing address (including postal code), daytime telephone number (including area code), and date of birth on a 3.5"x5" postcard and sending it with proper postage affixed to: (i) if a legal resident of the United States, District of Columbia, Puerto Rico, Canada or Mexico: P.O. Box 8629, Elmhurst, IL 60126; or (ii) if a legal resident of the United Kingdom: Disney Dream Giveaway, 483 Green Lanes, London N13 4BS. Participants may enter once per day during the Giveaway Period. All mail-in entries must be mailed separately, postmarked by December 31, 2007 and received by January 14, 2008 or they will be void.
Here is a link to the official rules:
http://disneyparks.disney.go.com/disneyparks/en_US/index?name=YOMDRulesPage all of the prizes are listed in detail in the rules!
Good luck on your trip! Have fun and Congrats on your upcoming wedding!
