First-person shooters are the obvious place to implement VR technology, but up until now most impressive Oculus Rift demonstrations have occurred in cockpits.
The stationary-pilot, moving-vehicle metaphor just matches the technology's current capabilities better. But this YouTube playthrough of a Half-Life 2 mode reasonably named Half-Life 2 VR is one of the most exciting applications of virtual reality I've yet seen.
Oh, hooray, you might say - an expensive headset (and, in this case, motion control system) to let us make shooty bang bang and look at explosions in more burning detail.
But really, it's the potential to goof around that gets me giddy. The player never actually leaves the training mode; instead he just runs around a simple environment as he gleefully tosses grenades over his shoulder, shines his flashlight around and reloads a revolver by miming the motions.
The best part? None of it's going to make you better at playing standard first-person shooters. Using that gear for a normal round of Counter-Strike would give you a really convincing view of the floor as your head gets ventilated by someone with his or her mouse sensitivity cranked up to 'caffeinated flying squirrel'.
It's just thrilling to be in a virtual world, even if that means taking some real-world limitations with us.