BoxWave has released a variety of accessories for the Palm Treo 680, including the Styra, standard Replacement Stylus, and Active Case, as well as Replacement Stylus for the Palm Treo 750.
Source: www.computingunplugged.com

Top 10 Treo Accessories
Although I have written multiple accessory guides in the past such as Treo 680 Accessory Guide; Treo 680 Case of Cases; Andrew's Essential List; Essentials: Getting the Right Gear for your Treo and Accessories Not In The Box ...
Source: www.federatedmedia.net