This is the first time I noticed these signs. This month they are all over the Hayes Valley area, and asides the SF Bike Coalition awesome membership discounts, I looked this up for more info about this and this is what I learned:
[From SFMTA] I Bike SF is a month-to-month, neighborhood-based program geared to encourage bicycling and support local businesses. Each month a new neighborhood in San Francisco will be featured and participating businesses in that neighborhood will offer bicyclists great discounts. All residents and visitors are invited: no fees, no sign-up, simply ride to participating businesses, present your helmet or bike lock key and get great deals.
May 2010: Hayes Valley.
Learn more here: SFMTA–I Bike SF
And with a dose of Blue Bottle’s New Orleans style iced coffee, I cheer for this program – very cool stuff. Now let’s get biking people!!