I tried the Xstylus Touch and a couple of cheap ones from eBay, and can't say it's been a pleasant experience. The XST works really well with the Ipad without a screen protector, which should hopefully indicate good compatibility with other capacitive screens, but no luck (i only tried it on my ION with a protector though). The cheap ones were completely useless. As keepitsimpleidiot stated, you are probably better off with your finger, if only for the fact that the soft buttons don't work the the stylii at all. If really necessary i can make a video demo testing out the different options.
Current devices: Xperia ION LT28i MIUIv5 (4.1.2), OpenPandora+Android, OUYA
Former toys: Nokia N97Mini - SE P1i - SE W800