Pat Tillman died today (yesterday in Afghanistan). He was 27.
Your mom's lesson of "If you can't say anything nice, don't speak" applies here.
If you see his family on the street, pay your respects. (Express sympathy, don't stare.) If his coffin passes in front of you in the coming days, show respect. (Remove hat, put hand on heart.) Other than offering assistance or kind words to his wife or parents, you're not allowed to say anything.
This young man was one of few who volunteered. Some do this with the blessing of their families, some do it against the wishes of their families. Regardless of that, it is a choice that they make with knowledge of the possible results. No one, not even family, is allowed to take away from that choice.
Pat had the fortune of being famous early in his life. Thus his death has drawn a lot more attention than others in the past three years. All deserve the same respect. Forget the fanfare and hype of Memorial Days of the past decade. Instead, when you're standing on the curb during the next Memorial Day Parade, think about what Pat and others gave up to do something they believed was needed, knowing what might happen. Put your hand over your heart or nod your head. Wish them well, wherever they may be.
If you have strong feelings for/against the war, find another venue to vent in. Pat's death (and the other's) is not a soapbox for you to stand on. You don't get to use it as "proof" for anything. This isn't the Viet Nam war where hundreds of thousands were drafted. Every single member of the military is a volunteer.
Ignore them if you want, most prefer it that way. They don't do it for the money (it doesn't pay well). They don't do it for respect (however pride has a lot to do with it). They, like others that died in responding to 9/11, do it because it needs to be done and no one else is willing to do it. If you can't understand why people do this sort of thing, accept it as something that you don't understand. Don't attach your own motives or politics to their actions (or deaths). Kathleen Parker has been able to explain it somewhat.
(Jerry Bowman, you're a no-class asshole. Show some sympathy for his family. Suppress your politics at least until after they bury the dude.)