I was intrigued to find that Miss C's brother has designed an iPhone App that involves tickling:
My brother designed another iPhone app to tickle your funnybone. Well, that's a side effect. What you're really doing is tickling rocks. Like the presidents on Mt. Rushmore, who will giggle (or maybe even guffaw) when you give them a direct tickle! Yes, I've tried it. There are 14 different stones you can tickle! Tickle Stones makes a great (and cheap) gift for anyone with a iPhone who needs a smile.
For 99 cents, I'm game so I bought it and wasn't disappointed. It certainly did what it promised, which is bring a smile to my face. I can't wait to show this fun and silly app to the kids :)