You could get this set of 3 styluses for the DS if you pre ordered Sonic Chronicles in Europe, somewhere. But which countries had this as a promo item? It's pretty cool, with Amy, Sonic & Eggman (rather than forcing you to have Shade, the new character, like the other set did) It was likely released to more than 1 country.
(Aside from giving away free styluses, it would be a wonderful addition if all styluses made could be combined into one pack and actually sold to the fans. Many people would want one with their favorite character.)