For years, I have maintained that the very best day of professional development in my year is the day of the CSTA CS&IT Symposium. And since I've always wondered if it was just me, I have been gratified both to see references to other people posting this thought on the web, and one notable year when in the symposium feedback I found out that someone wrote, "Wicked Teacher of the West said this was the best PD day of the year and she was right!" So you can take it from many anonymous strangers on the web that it's great!
For K-12 computer science teachers, this is a full day of PD just for you, with options whether you teach IT applications, AP CS, or anything in between - and not just high school either, there are sessions applicable to lower grades too.
The symposium gets better and better every year. The keynotes are thought-provoking, and the breakout sessions are full of ideas to take right back to the classroom. In fact, my biggest complaint about the day is that there are always multiple sessions I want to attend at the same time! And finally, the lunch is excellent - it's worth the price of admission for the great food and chance to spend time with other teachers!
Registration for the symposium is now open. It will be held on July 13 at Google Headquarters in Mountain View, CA. The registration is limited to 200 people and last year they did 'sell out' so I'd encourage you not to procrastinate. Registration information and more details are at the symposium website. (www.csitsymposium.org)
If you want to make it into a vacation, not only are there mountains, sun, the Pacific Ocean a short drive away, but Mountain View is a mecca for geeks, particularly the Computer History Museum, the Tech Museum in San Jose, and the Exploratorium in San Francisco.