I personally don't like to wear too many outward showing signs of my faith.
I wear a small OM but that's it.
One of the reasons is that I work with children and they may be of any faith or no faith and I want to be a neutral presence. If they ask I will tell them of course, but I feel strongly about separation of church and state and that goes for schools and other places too in my opinion.
I don't put tilak on after a puja, at my temple only some people do anyway it seems.
But as someone else said, I'm not Indian and people would most likely stare and wonder what it was if I wore it, I would feel a little uncomfortable.
Maya