Holy Father Nicholas
Today is my son's nameday and the feastday of St. Nicholas the Wonderworker and Bishop of Myra. Indeed a very popular and well known saint who has in recent years (decades...perhaps a centuries?) been secularized and fattened up into Santa Claus. Unfortuantely, Santa, though being a jolly fellow, is not the same ascetic who is also reported to have slapped (or punched - depending on translation) Arius for his offense against the Lord, at the council of Nicea. However, he landed in some hot water for doing so, so I would not advise doing the same to the JW's (modern Arians) on your doorstep.
But this little event aside, St. Nicholas is very well known for his love of and generosity toward the poor. The most well known story involves a poor man whose daughters were likely doomed to a life of prostitution for lack of dowery money and facing starvation. On three seperate nights St. Nicholas secretly left bags of gold for each of the man's daughters so that they would have food and a dowry - which if you think about it, is a bit different than little johnny getting a Playstation from Santa, but this is certainly where the "santa" tradition originates.
Much more is available to read about this great Saint's life, and one can begin HERE if they should so wish.
You appeared to your flock as a rule of faith,
An image of humility and a teacher of abstinence.
Because of your lowliness, heaven was opened to you,
Because of your poverty, riches were granted to you.
O holy bishop Nicholas, pray to Christ our God to save our souls.
You revealed yourself, O saint, in Myra as a priest,
For you fulfilled the Gospel of Christ
By giving up your soul for your people,
And saving the innocent from death.
Therefore you are blessed as one become wise in the grace of God.
...offered by Dn. fdj, a sinner at 2:33 PM [+]