Techcrunch parties: by reading Techcrunch. I have been to CrunchUp party, Star Trek and Avatar screening.
YC/Startup parties: Some people I know RSVPed on Facebook. I also follow several Twitter accounts of YC founders.
Entrepreneurs Helping Entrepreneurs event: Saw it on Techcrunch. I applied and got in.
TechCrunch parties <- how do I get in on that?
YC/Startup parties <- ditto
Entrepreneurs Helping Entrepreneurs event <- this sounds great, but how did you hear about this?
Lean Startup meetup <- this looks great! I will definitely be at the next one. Thanks. :)