With wireless technologies extending to every part of our daily lives, mobile networking applications are becoming increasingly popular for accessing the Internet. In this paper, we propose a peer-to-peer approach, called M-FTP, for mobile FTP services. Unlike traditional approaches, the proposed scheme implements a Collaborative Forwarding algorithm that takes advantage of opportunistic wireless connections, thereby improving network capacity by exploiting the diversity of network mobility. Using simulations as well as real-world network scenarios, we demonstrate that the proposed scheme provides a better mobile FTP service than traditional schemes, and thus facilitates more effective data transfer on the go.