A lot of times you can find good stuff for your house in alleys, like the cinderblocks and old door you need for a new coffee table. This Saturday, there will be even better, brand new, original accouterments for your dwelling in the alleys. Well, at least the one behind Walgreens on Central. A rogue band of artists is determined to use every available space to show art, including the nontraditional locales usually reserved for trash and broken glass. Thank you, brave creatives, for helping to transform ugliness into inspiration. “Art for everyone” will be in the thoroughfare from noon to 8 p.m.