EDIT: Please read all of this if you really want to know about Fastpasses! It took me a really long time!!!
How the Fastpass works...
You stick in your park tickets into a machine situated outside the ride, usually in a seperate (sepArate?) area. Then you get back a ticket that says you may return between a certain time...it is an hour span. For example, you may get 3:24 and 4:24. Fastpasses usually run out by around 7PM or 8PM. Often, the tickets are for HOURS after you put in your ticket.
Now, this is how I get Fastpasses, and we've found it is DEFINITELY the best way to do it...(Read it, it's worth it, I promise)...
Say you have a family of four people...mother, father, son, and daughter. All come into the park together. All want to go on Splash Mountain and Space Mountain. Mother and Father go wait in line for Space Mountain (as the wait is pretty much the same at both...about 80 minutes). Son and Daughter (or even just one of them, depending on how old the children are)...go...ok run...hehehehehehehehehehehe (can you tell I've done this a few times?) to Splash Mountain, taking ALL of the family's tickets to get Splash Mountain fast passes. It is 11AM. The fastpasses spit back out for 1:25PM-2:25PM (A typical interval). Then they run to rejoin mother and father at Space Mountain line. Warning: Children must be semi-passive-agressive to get through sometimes-glaring people to say "Scuse us, we're trying to find our party." Option for Space Mountain...squeeze through original doors, then go into the Fastpass lane until they reach family members and jump under/over the barrier again. (Actually, this is true for many of the ride). ALSO, often the line for Space will be SO long (or Splash, or any of the other impt rides) that the Mother and Father may not have even GOTTEN into the thick of the line yet. Whole family rides Space Mountain. It is now 12PM. They have 1.5 hours to kill. They may A)take a break, get a snack, relax. B)Watch a parade/show if they can plan it just right C)wait in line for another ride. At this point, the Fastpasses will be ready to use! Then you can go to Splash with no wait and it's completely worth it!!! Also, in that 1.5 hour span you MAY be able to get another set of Fastpasses, because on the Splash Mtn Fastpass tickets it says "Next Fastpass Available For..." and it gives you a time that you may get another Fastpass for ANY ride. However, what I personally still get confused about is how that time is calculated...? Two hours after you feed your ticket in? IDK. (Can someone who is reading this help ME?)
Other tips for Fastpass...
Go to the MOST popular rides in the parks to get Fastpasses FIRST. MK: The three mtns. EPCOT: Test Track, Mission: Space, and DEFINITELY Soarin'. MGM: ToT + RnR. AK: DEFINITELY DEFINITELY Expedition Everest, Kiliminjaro Safaris and Kali River Rapids. The reason to do this is that the Fastpasses often run out and if you are not planning to stay in the parks all day, the Fastpass times to come back change very VERY rapidly.
Any other questions??? Let me know!

Hope this helped!!!
Did I miss anything guys?
