This past time, I sent my kids on a scavenger hunt around the house and in the yard with little notes in each spot giving clues as to where the next clue was for example:
One note said "to infinity and beyond" so off they went to find one of their Buzz toys, then Buzz was holding a sign that said "yo ho, yo ho" so they went to my older DS's room to his Black Pearl. They had a great time! I had them running all the way up the spteps then all the way down to the basement and back up again and outside, in the fridge, cabinets, car, everywhere. This went on for about 10-15 minutes all the while them laughing the whole time. The final clue led them to a box under the couch that had a big set of Mickey ears that said "We're going to Disney World!!!".
Have fun!!!