Only a Word?

How often have you heard a request for "a word of prayer" or a "brief prayer"?  This strikes me as peculiar.  What single word can suffice for prayer?  Why do we need to limit the length of our prayers?  When was the last time you heard a long prayer in contrast to "a word" or "brief" variety?  The Prayer of the Church has developed into a responsive prayer.  This encourages congregational participation and breaks up longer petitions into "sound byte" lengths.  Do you pay closer attention to the shorter petitions? Does the Lord expect brevity? Where can God's people pour out their hearts to God together?  Under what circumstances is a longer prayer acceptable?  The Scriptures encourage us to pray without ceasing (1 Thessalonians 5) yet to avoid vain repetition (Matthew 6).  What is the balance and how is it attained? What are your thoughts?