I have used statements from volunteers attached with their pictures that read in a snapshot why they volunteer.  I have made flyers of these for posting in varrious locations around town, used them at varrious times in the newspaper and a few also appear on our website under the volunteer tab. 
A couple of years ago I began doing volutneer newsletters.  These are mailed out to volunteers and departments in the hospital (most of you prob already do this).  The purpose was two fold; one to use as another communication tool for volunteers and two to communicate to employees (this is not large newsletter just front and back of a standard page).  What I wanted to communicate to employees was...each volunteer is just not a person who has limited ability and elderly, I wanted to break the myth or prehaps the vison most have in their mind about the little elderly women sitting behind the front desk in a pink jacket.  I feature a volunteer; men and women, in each quarterly newsletter (yes, it will take me forever to highlight each one).  I interview them, I want to make sure I get  a few "funny" items in also.  I highlight their edcuation, leadership, jobs in or outside the home, etc. along with volunteer placement.... You all get the jist.  I interview them because it is easier for me to sing their praises then perhaps themselves.  That being said, I do indeed have many that would speak highly of themselves all day:) 
Hope this is helpful