Icons have a long tradition in Catholic circles, though to be more specific they have a strong tradition in Eastern Catholic churches as well as the Orthodox Churches. There has been a resurgence in recent years, in the west, of the appreciation for and reverence of icons.
But, icons are not just pieces of nice artwork. They are meant to be prayed with. They allow us to focus our prayer, using our senses - thus it is an incarnational prayer. Praying with an icon can allow us the glimpse into the divine that many of us are hungry for. Because they reflect such sacred mysteries, they can be venerated and should be treated with respect, especially if blessed.
Icons can be thought of as a natural outgrowth of a sacramental understanding of the world. God uses the created world to reveal Himself to us and to give us grace.
When an iconographer creates an icon, they are said to "write the icon", not paint it. This is because it is a prayerful exercise in humility before God. They are highly symbolic using shapes, colors and forms to symbolize different spiritual realities. They are not signed by the artist on the front, if at all. It takes a long, long time to become a master iconographer and becoming one is a calling, not a profession. The best iconographers are not famous artists, but holy saints.
"O Mother of God, the indescribable Word of God, became describable through you in the incarnation, for through the divine goodness the Word spoken from eternity became an Image: may we who believe in salvation both in word and deed clothe ourselves in the same Image." -5th Ecumenical Council of NiceaI have had a love for religious icons for a long time. I have quite a few of them, including three in my office. One was given to me as a gift after I finished grad school. The other two were given to me by my mother. I have placed photos of them in this post.
They are meant to be prayed with, not just be decoration.
For more on icons, I suggest:
-Icons in the Byzantine Catholic Church
-John of Damascus on Icons
-Orthodox Church Icon Info
-Wikipedia has a nice article
-Temple Gallery collection on Icons
"What the Book of the Gospels explains by means of words, the iconographer shows by means of his works." -Saint Basil the Great