I've participated in several guest blogger gigs at the International Association of Online Communicators (IAOC) and have enjoyed the great participation. You can see an example at Direct to Consumer News Releases: Do they suck?

The Fall 2007 season of This Week on IAOCblog takes place from Oct. 15 - Nov 16, 2007. Each week, an industry expert blogs about a hot topic in online marketing & PR.
I'm happy to see some friends and blogging buddies on the calendar including Dianna Huff, Ted Demopoulos & Shel Horowitz.
The Fall season kicked off September 24 with guest blogger Peter A. Gloor of MIT's Sloan School of Management, who blogged about analyzing workplace communications.
Here's upcoming the lineup:
October 15-19, 2007
-- Dave Taylor, Blogsmart, Ask Dave Taylor
-- Is It Okay to Get Paid to Blog?
October 22-26, 2007
-- Ted Demopoulos, Blogging for Business
-- Should CEOs Blog?
October 29-November 2, 2007
-- Dianna Huff, Marcom Writer Blog
-- Writing Search Engine Friendly Copy
November 5-9, 2007
-- Lois Kelly, Foghound
-- Conversational Marketing: Mood over Matter?
November 13-16, 2007 -- Shel Horowitz, Ethical Marketing Expert
-- Blogger's Code of Ethics: News or Ruse?