I remember Frozen Echo. I literally was stepped on by the spotter's pointer while I was "all ghillied up" and still evaded detection. Though, due to the season, there wasn't a lot of foliage cover to hide in. Subsequently, I had to stay pretty close to the ground in behind some thick brush. Though I was only 100 feet from the target, the brush prevented me from getting a clear line-of-sight shot. That Stalk competition was a lot of fun though.
I think a competition based on practical sniper shooting skills mixed w/ stalking, observation, and detection evasion, and precision shooting would work well.
Oh, and just for giggles, here is a pic of (call signs) Masada and Angel, from Memphis, at the Bad Karma Noob Day 2009.