Lots, but we do them standing. :)
Bowing and crossing (constantly) are such customs. On the Pentecost we do kneel and during the Great (Holy) Week we prostrate (but not on Sundays).
We have always found a way to accomplish that which was given to us and add our own customs without violating the Tradition.
One such example is the innovation (I believe 5th century) of placing the Body of Christ into the Holy Chalice containing the Precious Blood and for the communicants to receive the Body and the Blood, just as the clergy do.
I say to-may-to and you say to-mah-to ... ;-)