The ST-2 indoor shooting simulator is just the thing you need if you thought Duck Hunt was the awesomest game ever when you were a kid. They system is currently being used by the Russian and Slovakian shooting teams in preparation for the Olympics, and I want one installed in my basement. It's advertised as the "first simulator for shotgun and rifle shooting designed specifically for demanding users such as shooting instructors" and gives you feedback explaining what you did wrong should you miss a shot. You know, stuff like, "you have shitty aim", and "you were distracted by the couple having sex in the bushes". Which is a bad idea. Because one time I tried playing Duck Hunt with daddy's gun and accidentally shot stepmommy while she was vacuuming.
ST-2 shooting simulator keeps your aim sharp [engadget]
Thanks to Julian, who I've head can dissolve an entire urinal cake with a single urination.