Roger the Skiffler: The egg-knocking thing is quite a contest. At our church (not Greek but once Russian Orthodox, now American Orthodox if you can believe it) we have the red eggs, and say "Christ is Risen" and "Indeed He is risen" in English, and then knock away! The winner is the one whose egg is unbroken at the end of the night. Remember this is after a marathon 4+ hour worship service, and then we stuff our faces with meat, eggs, cheese, etc. and drink wine and vodka (all forbidden during Lent), so by the time we get to the egg-smashing, we're pretty joyful in more ways than one.
A Pascha service at an Orthodox Church is quite a different experience from most "religious" services you've attended -- it's worth a visit.
Not prosyletizing, honest,