Or the Act of Penenace, this part of the Catholic Mass, just after the greeting.
The priest says: My brothers and sisters (or similar wording), to prepare ourselves to celebrate the sacred mysteries, let us call to mind our sins.
Then, after a brief pause, all say:
I confess to almighty God, and to you, my brothers and sisters, that I have sinned through my own fault in my thoughts and in my words, in what I have done, and in what I have failed to do; and I ask blessed Mary, ever virgin, all the angels and saints, and you, my brothers and sisters, to pray for me to the Lord our God.
Compare with: Act of Contrition
Taken from: http://www.sonnet.co.uk/credo/missals.html, which is a page that compares the traditional Latin Mass, and the Nuovo Ordo the New Order of the Mass.