We introduce the Hocman prototype, supporting mobile group collaboration among motorcyclists. The design is based on findings from a field study. The motorcyclists are a group with a strong social commitment, however their mobile practice creates collaborative problems. They deal with it by using a website on the Internet, but collaborative issues still remains. For this purpose we have developed a prototype, based on web technology. The prototype is built for handheld computers and wireless communication, allowing the users to share rich content when being in the vicinity of each other. Keywords Mobile computing, CSCW, ethnographic fieldwork, ad hoc networking