I'm looking for a video clip (in universal format e.g. MPEG) taken
from on-board a 4-man bobsleigh on its descent down an Olympic track
(I've just been down one at La Plagne and was taking a video but
bounced hard, and pressed the "off" switch by mistake!)

I found a couple via search but they are very small and in a .mov
format.  You can find them here...

http://utaholympicpark.com/facility/pov_bsfront.html 

http://www.utaholympicpark.com/facility/pov_bsrear.html

Not sure if that is of any help at all or not.  Good luck finding what
you are looking for!