Somerville (bordering Boston and Cambridge) is home to one of the world's largest makerspaces: http://artisansasylum.com and a big cleantech incubator: http://greentownlabs.com/
I live in SF, but I have a special place in my heart for this area because the density and diversity of thought that you just don't get in SF/SV.
Yeah, the Cambridge/Somerville nexus is pretty amazing.