Well I myself use a hacksaw, it's light, has a thin blade, made for cutting metal, and seldom leaves sharp or uneven edges. The only problem is getting a straight cut, since the blade is so thin, it tends to bend easily, and can put a curve in the edge. The only way to stop this is to get good at cutting with a hacksaw.
I'm thinking about investing in a dremel, but I also want to go to college for stone, and metal sculpture, so I figure a dremel would be good.
Plus a dremel is a good drill for people who play games like warhammer, and other miniature games, since you can use it to customize your miniatures.