I gue foot tapping works for some but I am pretty much with Kendall on this. Some of the worst time keepers I have met in Irish sessions have been foot-tappers.I rekon, if tapping comes naturally, just go with it but do not try to force it - one can feel or sense time in other ways and I think it is a case of doing what you feel comfortable with (or just happens - I am crazy, when I am playing at my best, I see little dancers enjoying themelves in my mind) rather that trying to imitate what you have seen.
Jon