I didn't know that. So it's perfectly normal for an Orthodoxer to cross at any time upon hearing something especially meaningful to him, and when others do not cross? I've only been to a couple of Catholic Masses in my life and I didn't notice that. All the crossing I remember observing was in unison, once everyone was seated. (But, that could be wrong :)
crossing when ‘inspired’ is very common in orthodox parishes.
Yes, absolutely.
I've only been to a couple of Catholic Masses in my life and I didn't notice that
Oh, no, Catholicds do not ad-lib! :) In the RCC, everything is "prescribed." Orthodox churches have a more home-like atmosphere. That's because the church is our spiritual home, heaven on earth, we say. The church is where we, as the Cherubic Hymn says, "set aside all earthly cares." :)
In fact it may be bewildering to someone who walks in for the first time into an Orthodox church to see people milling around before the liturgy starts, or even during the parts of liturgy when the choir is singing.
You have to remember that most Orthodox churhes in the world do not have pews or even chairs (more of the 'home-like' setting then a theater or an auditorium) except for a row or two in the back for the sick and the old, and that we stand (symbolically resurrected) throughout the entire 2-hour service, so moving doesn't disturb people next to you.
Most of the movement during the liturgy is venerating icons to the side, or lighting candles for the living and the dead (usually separate candle stands).
All the crossing I remember observing was in unison
We do that in unison when the Holy Trinity is invoked, at the end of the Lord's Prayer (which is recited at every Divine Liturgy), etc. but throught the service you will see people crossing at different times. In some traditions (Serbian for example) when a priests blesses the people with "Peace to you" and he makes a sign of the cross, people "accept" the cross by crossing and bowing (remember that the priest is an icon of Christ, so we think of Christ' blessing us; we don't bow to the priest!)
When the priest or deacon insences people, we usually bow (Serbs also cross). Incesning the people is done after all the icons are insenced, because we are also the "saints" as you Protestants say, and in the image of God. So, our gratitude is expressed to God by reverence (bow) and invoking the name of the Holy Trinity in our minds (crossing).
There are other (but few) instances when everyone crosses in unison, but even then in Orthodox churches "unison" is poorly defined. Some people cross three times, others once! :)