I started noticing a lot of "via" links on blog posts leading to MetaFilter, so I eventually cut out the middle man and lurked for a long time before sign-ups reopened. Not a unique story, I suspect.
Super-friendly post-Katrina meetup
Not long after I evacuated from New Orleans in 2005, I ended up staying with my father in Berkeley, CA. The East Bay is now my home, but at the time I didn't know anyone in the area.
My arrival coincided with an East Bay meetup -- my first anywhere -- and I spent a wonderful evening with a friendly group of MeFites who made me feel at home when I needed it most. My profile picture is from that meetup, actually!