Question: Importance of Pentecost

How festively do you celebrate Pentecost? Christians in the U.S. place great emphasis on Christmas and Easter and they seem to forget about the great role of the Spirit in our faith. Pentecost seems to be an afterthought. I wonder if its changeable placement on the calendar conflicts with summer secular activities like graduations, proms, and weddings. Does its diminished signficance reflect something more fundamental about our faith and our image of God? What are you thinking?