Someone on Yahoo! Answers asked for a definition of "worship". A lot of ideas came to mind - ideas about hymns and joyful noise, about prayer reading of the Bible, and about spending time in holy silence with God. I think, though, that these are just the outer trappings of worship - these are the signs of it. These are the vestments worship wears out in public, but not the reality of what it is.
Worship is what is due God alone - that which we give God but no other. While worship has many outward signs - some very lively and some rather boring - it is what happens inside that defines worship.
When Mary Magdelene emptied an expensive perfume over the head of Jesus, she was worshipping. That money could have been used to feed the poor. That perfume could have been used in smaller portions, for many people. That perfume was purchased with (according to popular belief) dirty money. There are many reasons why she shouldn't have done that.But there is one reason why she should - worship. Nothing mattered at that point but doing something, anything for Jesus.
When two donate to the temple - one giving the tiny bit she had, and one a great amount but only a small portion of his worth, Jesus teaches His disciples a lesson. The lesson is not about donating to church, but it is about worship. The poor person that gave all of what little they had was worshipping; nothing came before God, not even keeping that little bit of money. The rich person was merely posturing - appearing to worship.
Worship often gets you into trouble. If everyone likes it and pats you on the back, its probably not worship. When Mary Magdelene used up the perfume, people were incensed. The next thing that happens in the Gospel story is Judas' betrayal - possibly spurned on by what he saw happen at that moment. Worship scares people. It makes people call you names. It makes people suggest that, while your faith is wonderful, maybe you should focus a little less on God all the time.