I decided to get a Wacom Splash tablet and it came in the mail yesterday. Pretty nice deal. It was something like 65 dollars. Wacom's are the nicest because their pens don't have batteries. It came with some art software, but after using it for a few hours, I found myself back to using Gimp. The art software makes it look like paint, but that's not really the look I want for games. It also came with Autodesk Sketchbook Express, which is more of a drawing program, but it had some limitations in the free version, like no transparent background. Anyway, most of us aren't the best artists but there is a world of difference holding a mouse and a pen. The pressure sensitivity is also cool.
I learned a few things while experimenting in Gimp that made me decide to get it. The pencil tool in Gimp is non-aliased, so it works well with the fill tool. The color picker is also nice, because you can fill and area, select it, and then do the shading without going outside the lines. I haven't tried it with Inkscape yet because shading seems like kind of a pain in it. I can get some decent looking art done in Inkscape, I just wish the UI was a little more intuitive.