You may want to check out Richard Bornman.
http://www.soundclick.com/bands/page...m?bandID=13286
He plays guitar but he uses fingers and alternates between thumb-index-thumb-middle-thumb-ring.
He has an amazing command of the instrument. I have been playing bass this way for a while though I'm just starting to incorporate the ring finger. I primarily play thumb-index-thumb-middle.
Matt Garrison notwithstanding, I think Richard's technique is the most efficient.