This is a funny and pretty easy trick, though it will require a little practice to get the timing
right. It's a great "bit of business" to do any time you use a sharpie for a routine.
Unfortunately, I don't think I'll be performing it often unless I come up with a way to modify
the gimmick. What you receive is the simplest possible thing that would accomplish what you see in
the trailer, and while I generally think simple is better, there's a significant downside in this
case. Because the writing end of the sharpie is exposed through the whole sequence, you're very
likely to accidentally get ink on your hands. I practiced for a while with a dried-out marker, and I
still didn't feel confident that I'd be able to do the necessary move without marking myself in a
real performance. If you're less concerned about that, or if you don't need to be able to write with
the sharpie (and so can use a dry one in performance) then I think you'll be very happy with this.
For me I don't think this one funny moment is worth walking around with sharpie on my hand for the
rest of the day, so it probably won't get much use.