One small step for man, one giant step for mankind.
I remember wondering whether it was supposed to be "a man." And I'm immensely disappointed that we've barely been back since, so the singular/plural issue has taken on a disturbing, almost sardonic, unintentionally ironic tone. But then, he was an engineer, not an English major, dammit!
Here men from the planet Earth first set foot upon the moon. July 1969 A.D. We came in peace for all mankind.