Well I've worked at a paintball field for a few years and finally decided to get some paintball pants. All they offer is some inbuilt padding around the legs, knees and groin (thankfully!)
Anyway I've stopped to take photos on the way home from work a few times and I've found these pants to be fantastic for photography if your going bush or needing to kneel down at all. The inbuilt padding around the knees makes it really comfortable to at the drop of a hat get down on your knees to get a shot. They also have alot of venting to keep you cool and they seem impossible to rip (touch wood)
Just thought I'd share that as I've found them really useful to the point where I'm going to get a 2nd pair of plain black ones if I can find them just for photography.
The brand I have are Dye and they release a new pair each year. For example the latest ones are called Dye 10's These are quite expensive but you can pick up brand new pairs of Dye 6's, 7's and 8's for a pretty good price. Same goes with a few other brands. Some of them look a bit funny like your going to a rave or something but very comfortable.

