I do all my digital drawings with a mouse still, but I use paint bbs. It's like...one step above ms paint in quality and options. About all it does that paint doesn't is watercolor, which I use in my shading a little bit.

Other than that, I've done some pretty passable art in paint with a mouse, too. I kind of enjoy the challenge, and I am also terribly afraid to move on to new programs like Photoshop for some reason. I'm taking a photoshop class this semester and I'm hoping it'll help. I've been doing more traditional stuff lately, though. I go back and forth.