I would first check if the device has any kind of pressure sensitivity. If it is, it will be compatible with Wacom's Bamboo Ink Pen or similar battery powered styli.
If your device isn't pressure sensitive, make sure to get a stylus designed Capacitive Screens. I would recommend one of Adonit's styli. I have used the kind with the clear disk on the end and found they are comfortable and responsive to use.
