The current Digital Journalist has a report on the Holi Festival in
Mathura, India. Danish Photojournalists, Klavs Bo Christensen and Carsten Snejbjerg cover it. The Holi Festival is a public riot of colored powders and water thrown about with great abandon. To protect their 5DMkII's in this envirnoment they took the following steps:
"In the end we wound up using gaffer tape to protect our Canon 5D mk2's. In the morning a fully charged battery and a 16 GB flash card were loaded into the cameras. After the cameras were turned on, they were completely covered in gaffer tape. We both used a fixed 35mm/1.4 lens that was now not possible to change during the day. Even though the camera was completely covered in tape, we could still use the most important buttons and operate the camera."
But one of the cameras severely malfunctioned upon returning to Denmark.
Full story here.
I still keep thinking the 5DMkII's (at least some) don't deal well with moisture.