[Martin Tell]

We Orthodox say it all the time, usually accomanied by low bows: at the start of morning and evening prayer, during the Hours, and before the Epistle readings during Divine Liturgy.

There's an interesting story on the origins of the Trisagion. Constantinople was experiencing a terrible earthquake. A little boy suddenly announced that he heard the angels singing the Trisagion (unknown on Earth before then). All the people began to sing the Trisagion and the earthquake ceased.

[Yudan]

You coming to PLC?