Lean Startup Circle describles itself as being for "Peer-to-Peer lean startup know how. It's a decentralized grassroots organization of Lean Startup practitioners all over the world".
I went to this homebage and entered my email as requested, thinking that was just the first step and there would be additional information required. Instead, I was immediately enrolled in a Google Group and informed that I would be receiving an email once a week from them. The Google Group does look moderated, and the questions to seem serious and thoughtful so while I didn't care for the way they got my email, this aay be worth visiting from time to time - especially if anything in their weekly archive email is of interest.