I wanted to buy a Samsung Galaxy Note because of the stylus, but I found out (as many people did ) that you don't need a special smartphone for that. Smartphone's touchscreen work by detecting body capacitance, you can do the same with a capacitive stylus:
Most of them aren't expensive, I got one like the one of the bottom at 15ARG$ (about two dollars)
You can also make your own stylus
I'm currently using
Sketcher has armony brushes, they let you draw pretty fast, but you don't have too much control. So I use it for sketching and then I paint over it with Sketbook.