My girlfriend uses an "Ewa-Marine" with her Nikon D50. It's a clear,
flexible case, the cheapest way to waterproof an SLR.
http://www.rtsphoto.com/html/ewamar.html
I see Amazon sells several models:
http://amazon.com/s/ref=nb_ss_gw/102...0&Go.y=0&Go=Go

Steve