I use e-mail like crazy. Most volunteers have it, and with the number of recruits I have, I don't have time for phone contact. I send out weekly (at least) emails to let everyone know what's going on. I ALWAYS thank volunteers for how they have directly help the clients, not how they have helped staff, or the organization. They are there to help us, they want to help the clients directly, so that's what I focus on. It really changes the whole attitude of volunteering and produces a greater response!
Sheryl Simons