I've never had one on my keychain because keychains are the bane of my existence; the smaller I can get away with the better. But, I've carried either a leatherman PS or a Vic rally for the past year a lot of the time. I think the rally is the better tool because it has a Phillips head. I carry the PS more because it doesn't have a blade, and I don't have to worry about remembering I have it if I have to go through a metal detector. There is no multitool that I actually really like. So, I've ended up with a small organizer pouch with miniature tools that I think works better. It's not as convenient, but it actually seems worth the weight to me, which nothing else really has. I still need to find little scissors and a small pair of pliers for it, but I'll be happier when it's done.