Vain Repetition in Prayers, What Does it mean? Matthew 6:7  New Living Translation
  "When you pray, don't babble on and on as people of other religions do. 
  They think their prayers are answered merely by repeating their words again and again.


I still find it difficult to explain to myself what this scripture is about.
Is it that when we pray, we should avoid repeating a certain phrase or word or sentence or what ?
As far as I can determine from other Scriptures it is not the actual repetition of things, but the fact that there is a lack of sincerity in that way of praying. The full intent of Matthew chapter 6 lies in the fact that Jesus is really warning us that:


  1 God knows our hearts and when we are praying we are talking to God and that we should be seeking his attention and that to the exclusion of all else.
  
  2 When we pray in a manner that is more to seek the approval of those around us that that will be our reward, not the grace of God.


Notice these Scriptures from Chapter 6 in the King James Version:


  Matthew 6:1 Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven.
  
  Matthew 6:5  And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward.
  
  Matthew 6:6  But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.


I do not believe that Jesus meant that we should physically go into a closet to pray, but was instead saying to keep our prayers secrets between God and us.

Finally consider this:

Mat 6:7 and 8   KJV


  7  But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking. 
  
  8  Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.


Notice that in the second part of verse 7 he says that they think they will be heard if they repeat their request often enough.

So does that mean that we should only ask for something once, to my way of thinking God can remember your request even though you only ask one time, and if I read the second part correctly it tells me that an all knowing God already not only knows what want, but also what I  truly need. So if something I want is also something I need He will grant it.