Wasn't therre a little controversy about the measurement aspects of Phelp's win? I think the cameras shows that the competitor could have touched the end of the lane first. But there is a switch that has to be lightly depressed from the swimmer's momentum when they touch it, and the competitor was stretched out trying to touch the wall first, and slowing down. Phelps gave the wall a strong jab, and won.
Yes, the biathlon is a strange event. I've always thought it would be more interesting if it combined alpine (downhill) skiing with machine gun shooting, simultaneously of course! I can hear the Olympic announcer now, "And James Bond from the UK takes the gold!" IIRC, such a scene was in The Spy Who Loved Me. Correct me if I'm wrong.
In the winter, nordic skiing is my primary aerobic exercise ("skating" technique, not classic). There is a nordic lodge not too far away that will give you one day training on biathlon- gun and all. I plan to take the training one day, just for the uniqueness of it.
Marksmanship is an Olympic event for the summer games, so I don't think it is so strange to have an event with firearms in the winter as well. I've never heard of a firearm-related injury during one of these events, so I don't think it will be eliminated.