Figure some of you would have already received this, but if not, there's a new race in town:

 

Communities of Opportunity would like to thank you for participating in the Stadium-to-Stadium 10K over the past four years.  Our race has been a success in many respects and that was because of your help.  This year, the Stadium-to-Stadium race will be integrated into the First Annual Giants Run on June 14, 2010.  We urge you to support either the 5k or Half Marathon, both of which will finish at Home plate at AT&T Park.  Register at www.thegiantrace.com and use the promotion code ?STADIUM? to receive $10 off the half marathon or $5 off the 5k entry fee.  If you register early, you can receive a free ticket to the June 11th A?s v. Giants game.  Supplies are limited, so act fast. 

They have quite an extensive website for a 1st-time race, including course maps.  It's also nicely timed as an HM before the SF Marathon at the end of July.