For all new to or planning on coming to Seattle there is a Hacker News meetup that recent started (http://www.meetup.com/HackerNewsSeattleMeetup/events/2752013...), I haven't been as I live up north and driving into Seattle is something I try to do as little as possible for my own sanity. There is also a local startup group (Seattle Tech Startups: http://seattletechstartups.com/doku.php) who have occasional talks at the UW campus as well as a fairly active social calendar (http://www.seattletechcalendar.com/). Then of course there is the UW which has public lectures, Bill Gates is giving a talk next week I believe (just saw an e-mail invite for it today, but alas I am gone on vacation next week).
Yep! I run the events, and I was looking for a good place to plug them on this thread... :) They're wildly successful (120 RSVPs in ~24 hours for this latest event...), and there's free beer and free pizza.
I'll be posting it to HN early next week, but if you RSVP now you'll have a much better chance (I'm capping it at 200 RSVPs).
I do wish there were more Hacker News meetups on Eastside, though ... getting over to Seattle is a bit of a drive, and compared to Bellevue and Redmond, hellish traffic and roads.