Some of my favorites:
*Bring a compact water pistol. Make loud sneezing noises while dusting the neck of the person in front of you. If you get a nasty glare, apologize profusely and say you're pretty sure it isn't contagious anymore.
*Loudly speculate on how your kids are doing back home since you were unable to procure a sitter. Make it clear they will suffer grave physical abuse if they've touched your prized golf clubs collection. Observe the reactions you get.
*Visit a counter service food location first. Contendedly gnaw on your burger and fries in line. At around the 20 minute mark of the wait, turn to the person behind you and say "This place better have damn good drinks when we get up there!"
*Regardless of the attraction, start loudly relating the story of "that kid who died on this thing." Bonus points if you create a plausibly gruesome story for a Fantasyland attraction.
*Get the attention of a parent with an adorable child close to you in line. Start talking about how you'd just love to take her home with you. If the parent smiles, blushes or says "thank you," continue along this train of thought. Describe how you'd love to just put the child in your car and take her home to spend the rest of her life with you. Describe what a good parent you would make and how well you would treat her in suitable detail. Look at the parent with an expression suggesting this arrangement should be considered.
*Wait for a rather ordinary person to walk past the queue and say in shocked excitement "It's Mickey!!!" Try to wave the person over to your location. If this is successful, step briefly out of line to pose for a photo with the person, enthusiastically relating your excitement at his presence. Ask for his autograph. Bonus points if you kiss him on the cheek.
*Look for a family with mouse ears and T-shirts with their names on them, the assumption being that they might know a good bit about WDW. Strike up a conversation and ask them if they've been on Spider-Man at Disney/MGM Studios. If one of them tries to correct you, argue your position with increasing belligerence. If the other person still doesn't back down, ask "You wanna take this outside?!?"