Jens Anso Carabiner
Anso is a knife designer whose blades have been picked up for production by Spyderco and Boker. He has a certain flare for gear and his Carabiner is no exception. It is made of green, blue, or gray Ti and has a custom stainless steel spring gate. It is a full custom item and available from Anso and a few resellers for about $125.
D22 Uncus Ti Carabiner
What I like about this carabiner, aside from the material (ahhhh! Ti), is the design. It is actually DESIGNED to be a keychain tool. Some of these utility carabiners are still wedded to the idea of looking like a climbing carabiner, which is nice for climbers, but limits their utility. Here this guy looks like it could be useful in a bunch of different applications.
Cool Fall Droid 58
This guy was included in my review sample Sidekick and it is actually quite nice. Unlike these other utility carabiners this one has two tools built in--a bottle opener (because you need another bottle opener, right?) and a small hex hole for use as an oxygen wrench or a place for a driver bit to rest while in use. All of that for $5.00. It may not be a Ti beauty, but it is pretty darn useful.
I have been carrying the Leatherman Carabiner and it is not too bad at all. It is thin and light with hooks in the right place. I wish the gate would open a bit more, but it is not that bad. It is a good deal for $5.00