Here are some images I've done lately. For modeling I usually use Blender, which is an open source modeling/animation suite. It's an awesome piece of a software. Other programs I've used here include GIMP, Inkscape and LuxRender, all free programs.
1-up for the birthday boy - A birthday card I made for a friend of mine's kid who happens to be the biggest Super Mario fan I know:) That's him in the middle. He was very curious as to where did I find a card like that:)