When you pray, do you speak differently?  Do you start speaking in a style that is foreign to your everyday speech?  Do you notice when others pray and they change their speech habits when entering 'prayer mode', or say their routine phrases?  Do you drop some obscure verse making sure to note the reference when praying in front of other believers?  Are you preaching a sermon to the people around you?

My wife has caught me a number of times repeating a phrase or words that I never use in regular speech and when she brings it up, I have to respond with "I wasn't really thinking, it's just a habit I guess."  Of course I feel remorse for addressing God in this manner; even when I may not notice it, God knows.

Now, we cannot judge others, we cannot tell if their prayers are genuinely from the heart, if they are putting on a show for man, or if they are genuinely pleading with God...  BUT we can and must examine ourselves. 

Do you have your favorite lines, that just roll off the tongue without thought?  Are you lazy in prayer?  Do you realize that your audience is God, not those around you?  Do you realize that you are approaching the Creator of the universe, the perfect and all-knowing God?

What a humbling thought.  May we all pray with reverence to our great God who sees the very intentions of our heart.

PS.  On a practical note, taking a silent moment before prayer to collect your thoughts and consider who you are addressing is a valuable habit.