Dutch hooks should work great for opening beer. Last year while hunting I used a door latch on my van, this year while dumping beer I used the latch plate on a door. Both of those methods are a little wasteful. In college I would put the edge of the crown cap against the top egde of the counter and smack the top of th cap. Much less waste. Handcuff keys work well.
But, then again, when I homebrew I tend to keg, because I am incredibly lazy and into instant gratification.