I had the pleasure of attending the first Javascript SF meetup at the Hi5 offices a couple days ago. It was a rather large turn out with some great demos. The main themes of the night were Canvas and Javascript frameworks to develop desktop apps. A few thoughts on the talks:
First up was SproutCore presented by Charles Jolley which is what I would imagine if Javascript and Ruby on Rails had a love child together. The basic premise is to allow you to develop desktop type apps with javascript and ruby. The best part of the app is the build system which merges all your javascript and css, even spriting your images.
After SproutCore, Douglas Crockford came to pimp his new book JavaScript: The Good Parts. Ajaxian joked that it would be a 2-pager at most 
but Crockford said it would easily the densest book about javascript (weighing in 120 pages). A quote from the book:
Most programming languages contain good and bad parts, but JavaScript has more than its share of the bad, having been developed and released in a hurry before it could be refined. This authoritative book scrapes away these bad features to reveal a subset of JavaScript that’s more reliable, readable, and maintainable than the language as a whole-a subset you can use to create truly extensible and efficient code.
I’ll definitely be picking this one up.
Somebody (I don’t recall who) mentioned flotr, a javascript charting library. It’s been around for a while but this is the first I’ve looked at it. There are definite benefits in doing charting in canvas versus flash but my worry is IE6 and 7 support. Even though IE 6/7 are supported through ExCanvas, I still don’t feel comfortable with the landscape.
Easily the best presso of the night was from the 280 North founders showing off not only their upcoming app 280 Slides but the framework that it is built on. Ross Boucher and crew asked the folks to keep the wraps on what was shown at the meetup so I won’t delve into it much more. All I can say is the app is far superior to any of the current online slideshow offerings out there right now. It basically looked and functioned (very speedily too!) like a normal desktop application. The framework which has been in development for over 2 years is unlike anything out right now. I’m not sold on it yet but they stated that their plan is to open source it so I’m looking forward to getting my hands on it when they do.
By far the funniest moment of the night was when Yehuda Katz was demoing ruby-spidermonkey. Right before he showed an example using ‘with’, he turns to Crockford and says “Sorry Doug”. 
The entire room started laughing which meant everybody in attendance was a bonafide javascript geek. Awesome.