The rest of these pictures were taken in 2005. I've made extensive modifications from my original setup so I thought these would be better than an earlier version. I'll start with some close ups of my helmet.
I had a problem with air flow and my glasses fogging so I cut out the frown and installed window screen mesh. I got a roll of plastic mesh for $6 at Home Depot, enough to replace an entire screen door. I doubled up the mesh to keep people from seeing through it.
I got a pair of fans for inside the helmet to improve airflow. I bought mine pre-assembled as a mod-kit on Ebay but you could just as easily buy parts at Radio Shack. Both fans run off a single 9V battery and a fresh battery can last for about 5-6 hours of trooping. I used split loom ribbed tubbing to keep the wire in check and bought battery holders from Radio Shack for the 9V's.
I've found that not having a watch can be annoying and since there's nowhere to carry one easily on a trooper costume I glued an old wrist watch inside my helmet.