I'm quite fond of the
iFaraday stylus for use on capacitive screens... the tip is covered with a metallic fabric that is pretty responsive, and there's several options for tip shape and level of firmness. From what I understand, the guy making them will do customizations (longer/fatter/whatever) when asked. I just have the most basic one ($10 which may seem like a lot, but keep in mind that they're made by one guy working out of his home in Southern California and not some mega corporation using cheap labor) but it works great on my iPod Touch.