The G-10 UKPKs are great 3" knives. The choil gives them plenty of handle (I wear an XL glove, and even that is a little snug), and being slipjoints, they are pretty law safe too. The design makes them safer to use than normal slipjoints as well, mine function quite well as work knives too. Still if a lock is an absolute must, the Caly 3 is the same knife with a lockback.
I really like my Spyderco Sage 1 and Sage 2, but I found their handles were a little bulky in the pocket for only having a 3" blade. The quality feel on them is great though, and they are one hell of a value for the price.
I found that the MiniGrip handle felt small in my hands, its a 3.5 finger handle. If you get custom handles, they can really make the blade shine though. I have a Cuscadi handled Ritter MiniGrip, and it fits my hands very well.
For pure small and light, the CRKT Eros is a lightweight dream. 1.3 ounces, Ti framelock, 3" blade, IKBS flipper, and the handle fits my hand as well. Much better than the small Seb did (which was a 3.5 finger knife for me too).