John Maxwell is an author and speaker and pastor who has written over 50 books, primarily on leadership.
The following websites appear to host free MP3s of his material:

• http://www.vitalifefitness.com/audio/by/artist/john_maxwell
• http://server.firefighters.org/2002catalog.asp
• http://freebiesforlife.blogspot.com/2008/01/free-download-john-maxwells-favorite.html
• http://odeo.com/episodes/11396763-Dr-Bill-Bright-and-John-C-Maxwell-Episode-26
• http://gochristfellowship.com/grow-deep/sermon-archives/

You can also download MP4 videos here:

• http://www.cbn.com/media/index.aspx?s=/vod/JohnMaxwell_091307&title=The%20700%20Club&prgm=700club
• http://video.google.com/videoplay?docid=-4983057899447761685

There are more videos here, some of which are for online viewing only:

• http://video.google.com/videosearch?q=John+Maxwell+&emb=0#

If anyone has any more links, please let me know and I will add them.