Screaming Penguin - Source Does Matter

If you are in or near the big Apple it might be worth checking out AjaxWorld.

Even though the conference organizers don't know the correct way to spell Ajax (lower case), and it seems like a bit of a corporate circle jerk from all the content on the site, there are still some good speakers in the lineup. Looks like many interesting angles get coverage: different toolkits and approaches, security, performance, mashups, the "enterprise," mobile, offline, and more.