I did something very similar just a few weeks ago. A salesperson was trying to convince a couple to purchase a more expensive Canon. After listening for a few minutes, I told my wife to play along. At that point, I picked up the K10D and started telling my wife about it like I was trying to convince her to get one (she already has one, by the way). Everytime the salesperson said something about the Canon, I mentioned a similar feature on the K10D. And the more I talked, the more the couple were distracted.
I then went further to talk about shake reduction. My wife, now aware of the game, asked if another Canon on the shelf in front of us had shake reduction. When I said it and most Canons didn't (had to buy expensive lenses with that), she then commented about how expensive that Canon was compared to the K10D. At that point, the couple lost all interest in the salesperson. I went on to talk about sensor dust reduction, moisture seals, and how great the camera felt in one's hand. After holding the K10D for a few moments, my wife finally agreed she really wanted one for Christmas and we walked away. A few minutes later, I looked over to see the couple asking about the K10D, with the husband holding the display model in his hand.
We paid no more attention, going on about our own shopping in another area of the store. However, while in the cash register line some time later, the couple passed by with a camera bag in his hand. At first, I was disappointed to see the Canon logo on the bag. However, the couple saw us and slowed just long enough to tell my wife he had purchased the Pentax also. I said it was a great camera and good luck with it. We then exchanged Christmas greetings as they rushed out the door.
By the way, the Circuit City price for the memory card is a good deal. I would rush down to buy one, but I think the nearest Circuit City store is about 2,500+ miles away.
stewart