Capacitive styluses are thick, yes. But I prefer a stylus to fingers for drawing/painting or writing. Like Tom, I use a Wacom Bamboo which is one of the best I think in terms of precision, but it's still thick.
make a stylus with a fine tip, reviews on Amazon are mixed though. And they have announced a pressure-sensitive stylus, which I find very tempting even if it doesn't work with every app. I'm waiting impatiently for it to be available.