Disciple - Grow, engage and monetise your community with Disciple community software. Get your own branded community platform on Web, iOS and Android
PodBooker - The easiest way to get booked on podcasts
Forumotion.com - Create a free forum : free forum hosting, free forum skins, templates editing, chatbox, RPG mod... Choose PhpBB 2 - 3, Invision or PunBB. Create forums now!
PodKoi - Find podcasts to be interviewed on & guests to interview.
Proboards - ProBoards is a host of free forums with customer service.
Speaker Directory by HeySummit - Guests for your next event or podcast (or submit yourself!)