SB Nation, the fan-centric sports blog launched by Kos.com founder Markos Moulitsas Zuniga and Tyler Bleszinski and run by former AOL EVP Jim Bankoff, is launching 20 regional sites this month. The sites, themed “your new local sports page,” are expected to complement SB Nation’s 255 sites that are oriented around sports teams, and will use SB Nation’s “Story Stream,” a real-time news format. The sites can be expected to compete against local newspaper sites, and local hybrid Web and TV sites launched by ESPN, Fox, CBS and Comcast (with which SB Nation has a content sharing relationship).

SB Nation, which has 29 full-time employees and is based in Washington, D.C., will leverage existing content from its 300+ paid contributors, expanding some of their roles. The launches begin this week with New York, Washington, Chicago, Boston, Phoenix and Detroit. Next week, 14 additional cities will be launched. Each launch will be accompanied by local meet-ups, featuring giveaways, raffles, and food and drink specials.

SB Nation has raised $13 million, most of it in 2008. Institutional investors include Accel Partners, Comcast Interactive Capital and Allen & Co. Individual investors include Bankoff’s former AOL colleague Ted Leonsis, and former Yahoo execs Jeff Weiner and Dan Rosensweig.