After the best debate ever in an Upper Canada Catholic combox, I can now tell you how Ash Wednesday (my first as a full-fledged Catholic) worked out:
I left the ashes on, and decided to see what the reaction would be instead of just making assumptions. When I got back to the office, I looked in the mirror and saw that my whole forehead was covered in ashes - I didn't look like a penitant, I looked like a chimney sweep! So I washed off all but a one inch circle and went about my day.
Let's just say I now I know how women feel when men talk to their chests. But on par - no real problems - just a lot of staring.
Thanks to everyone who took the time to comment.