CheapyD from CheapAssGamer has recently made a very informative video-review of 3 different DS styluses which may solve (or not) some of the issues you have with the original one.
The winning Stylus (of this review) is the Hori pen which is available from this link (non-affiliate link). But my personal favorite would be one of these metal retractable styluses.
[Via Kotaku]
