I just got a Kershaw Hotwire. It pops open with one hand and locks solidly. I tested it in the store along with a few low cost, one hand opening knives and was surprised. The precision and quality you get for under $20 is amazing.
As a kid I was fascinated with switchblades but they were illegal. I guess people thought all only a criminal would need one. Now even automatic knives are legal in many states.
I got home and flicked open my new knife to open some boxes. How handy is that to have one hand free to grasp the box while you safely open and close you cutting tool with your other hand!