Fast Passes are the greatest thing! Only certain rides/attractions offer these. Simply place your ticket/card into the machine and it spits out a ticket w/a stamped time of when to return to the ride. You then enter through the "Fast Pass" line and pass all the poor people standing in the standby line. Best to use this in the AM as the more popular rides can distribute all their fast passes for the day in the afternoon. We missed Space Mountain because of this on our last trip but won't make the same mistake next time. You cannot get another fast pass until the return time stamped on the ticket (i.e. if it tells you to return between 10:30 and 11:30 then you can get another fast pass after 10:30) or two hours later, which ever is sooner. It may sound confusing, but trust me after you use it once you will get the hang of it. Even if lines are short, still get the fast pass. You can never turn a fast pass in early, but you can be late. So even if you're told to return by 11:30, don't worry if you get there later than that. You'll still be allowed on. But know that you will need a fast pass for every member of your family. You may also want to select one person to be the "fast pass runner", send that person to collect the fast passes for everyone in your group instead of everyone walking around. It's quicker that way. Sorry if this seems long - but you will love the time you save.