A Bold and Impromptu Approach to Fourth Dimensional Telepathy

Here is a quick idea:

Hand out slips of paper to you specators to write ANYTHING they want - no forces here. Have them fold the paper as to obscure the wrting inside. Now, casually take the first person's slip of paper and then say, "wait a second. Lets do this another way. Here place your paper inside these envelopes." as you grab the envelops off the table you switch the first person's paper for a dummy. You hand person one the envelope and then the dummy to place in the envelope. This is all done casually as to not raise suspicions. Now hand the other two people the envelopes and tell them to follow suit.

What you have now is two sealed words and one sealed dummy billet. The real billet can be peaked at anytime now to see the word and you are set up for your one-ahead without having forced anything! If you are worried that it may look suspicious tell the spectators to hold onto the envelopes until later. Move onto something else and come back to this for the closer. The time misdirection will make them forget about any funny business plus you get a longer opportunity to peak the stolen billet.

This is particularly useful in impromptu situations when someone asks you to do something amazing and you don't have anything prepared. All you need is three people, a pen, paper, and some envelopes (most people have envelops laying around the house).

This can play strong because they can think of anything they want. Tell them to make it difficult for you by coming up with all kinds of insane things.

With a little bit of thought and planning you can hand the slips out again at the end too!