Radio Days Revisited BlogTalkRadio seizes on an overlooked market niche--and a new round of funding.

When Alan Levy's father, Maurice, was undergoing treatment for non-Hodgkin's lymphoma in 2006, Alan created a blog for Maurice to document his experiences. Although the younger Levy owned a telecommunications company, he knew little about the world of social media. But as he investigated the blogosphere, he saw opportunity.

"I thought it would be interesting to let bloggers--or really anyone--host their own talk shows using the phone," Levy says.