Cosmic Landscapes Radio Network
Rebroadcasts the USA's best sci-fi radio shows with programming updated daily.
http://www.cosmiclandscapes.com/

FanBoy Radio
A weekly talk show about the comic book industry.
http://www.fanboyradio.com

Hour of the Wolf
Broadcasting a two-hour show live over WBAI (99.5 FM) in New York City on Saturday mornings from 5 thru 7 AM (ET). Topics are eclectic but usually deal with writing, science, science fiction or fantasy topics.
http://www.hourwolf.com/

Interstellar Transmissions Radio Program
A live radio talk program on science fiction and related genres broadcasting on WWNN-AM 1470 Friday nights.
http://www.interstellartransmissions.com

I-SCI-FI
Internet-only sci-fi broadcast which manages to take live calls. Archives in MP3 format.
http://www.i-sci-fi.com/

Mike Hodel's Hour 25
Science and science fiction news and interviews.
http://www.hour25online.com/

Near-Life Experience
Hosted by Wendy Wallace, NLE is a weekly talk show featuring interviews with compelling people from all walks of life.
http://www.wendywallace.com/nle/

Sci-Fi Talk
On-demand, internet only sci-fi radio. Many interviews.
http://www.scifitalk.com/

Sci-Fi Zone
Saturday from 11:00 to midnight, EST. Listen to live or archived shows.
http://sci-fizone.com/

Shock Wave Radio Theater
Sci-fi talk show. Archives, in RealAudio format, are regularly rotated.
http://www.visi.com/~romm/