From "The Royal Road to Card Magic" comes "Rapid Transit", a very commercial card effect that is woefully under-rated. The basic premise: Two card are selected (FREELY) and they transpose (change places) under the watchful eyes of the audience.

This is still one of the strongest types of magic one could perform for any audience. The only reason I avoided this effect for the longest time was the handling as depicted in the book did not suit me - I didn't like the contact of the card to the deck. Years later, I worked out a handling that I felt worked for me: it gave the impession that the cards were never touched after the selection and isolates the transposition to the hands of the spectators. This works for me: I hope you'll find it effective for you too. :)

1. Turn to the spectator on your LEFT. Have a card selected by riffling down the LEFT long side of the deck with your LEFT thumb – riffle force style. This is a free choice but you need to force the next card using the riffle force, so it's a good idea to maintain consistency throughout. Have the spectator call out "STOP" anytime.
   
   
2. Do a swing cut at the point of the deck where the spectator called stop and place the top half below the bottom. With the deck in mechanics grip in left hand, perform any double turnover to show the face. Show the card – let's say the 7D.
   
   
3. Do another double turnover to turn the double card face down. Deal the indifferent card face down on the table TO YOUR LEFT, retaining the 7D on top.
   
   
4. Perform a simple swing cut, apparently burying the 7D (top of deck). Retain a break between the two halves.
   
   
5. Turn to the second spectator on your RIGHT. Give her the same instructions as the first – call "STOP" as you riffle your thumb down the side of the deck. Perform the riffle force.
   
   
6. When the 2nd spectator calls 'stop' she have 'selected' the 7D. Perform another swing cut at your break (forcing the 7D) and again place those cards you have cut originally from the top below the original bottom half.
   
   
7. Perform another double lift. You will show an indifferent card – suppose it is the KC. After drawing some attention to the KC, do another double turnover to turn the KC face down. Deal the top card (really the 7D) onto the table to your RIGHT miscalling it.
   
   
8. Now, as you explain the premise of the effect (whatever patter you might have decided to use), pick up the supposed KC on the right in your RIGHT hand. At the same time, your left hand (with the deck) swings to your LEFT and picks up the indifferent card on the table in your LEFT hand while the deck is still in your hand.
   
   
9. As you patter, reinforce the supposed positions of the two cards – the 7D on the LEFT (move your LEFT deck hand up and down as you emphasise this, coalescing it with the top card) and the KC on your RIGHT (move THAT card up and down as you emphasise this).
   
   
10. Turn over the RIGHT card as you simultaneously perform a push-off stud second deal with your LEFT deck hand.
    
    
11. TA – DA! The cards have changed places!