If you have children do you let them believe in Santa Claus (and I dont mean St Nicholas either)?

I'll teach about santa. I'll also teach that christmas is a time for giving and loving, I plan on having him choose something he really wants and give that gift to toys for tots (or some similar program) every year. That way he'll learn that we care during this holiday. I will not use it for behavioral technique. That only works when the end of the year is and it becomes more of a selfish activities then anything else.