Originally Posted by el twe
I wouldn't be surprised. I was just under the impression that randonneuring was a transportation (ie touring) ride, but the OP seemed to mention an organized longish ride, so I assumed charity.
Here's sheldon's definition:
http://sheldonbrown.com/gloss_ra-e.html#randonnee
Basically: Long, semi-organized ride, but not a race. I bet that charity rides came from randone events.