I took this picture today in Pueblo, Colorado. They also bought the other side of the billboard and it has a different message.
The thing that is just so painfully obvious to me is that Catholics do, in fact, worship Mary. Talking to someone who is dead, and expecting them to be able to help you, seems a lot like worship to me. I realize they don't think of Mary as God or a god, but they think she can hear millions of prayers at once, and she can at least attempt to persuade her Son to do something.
While it's obvious to me that they're attributing abilities to Mary that belong only to God, and that prayer is an act of worship to be reserved for God alone, I'll just quote a couple of standard Catholic prayers to Mary, and everyone can decide for themselves.
Hail Mary
Hail Mary, full of grace, the Lord is with thee; blessed are thou among women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners, now and at the hour of our death.
Amen.
Morning Consecration to Mary
My Queen, My Mother, I offer
myself entirely to thee.
And to show my devotion to thee,
I offer thee this day, my eyes,
my ears, my mouth, my heart,
my whole being without reserve.
Wherefore, good Mother,
as I am thine own, keep me,
guard me as thy property and possession.
Amen.
Origin: http://wizard-notes.blogspot.com