I'm sure that everyone "holding up the tower" knows that they're not being original. And most likely they know that they look silly. But they do it anyway. So I say good for you, tower holders.
Who would be more fun to sight-see with: them, or those who snicker at them, consider themselves too sophisticated for cliche photos, and secretly wish that they had the guts to do it?
Course, if you have photoshop, you don't have to look silly. You can photoshop your face onto someone who was bold enough to go to Pisa and look like a tourist.
See, no "looking like a tourist" involved. Though, if you are a tourist, aren't you supposed to look like one?
Anyway, once you have the photoshop out, you may as well use it to put yourself in all the places you didn't have time to visit:
There. Done. Vacation pictures accomplished.