Is this weekend! April 12 and 13th, at the Washington State Convention and Trade Center (800 Convention Place, Seattle). The Green Festival is charging $15 for admission for one or both days, unlimited access, unless you donate 3 books, and then it's $5 off admission. I think you also get a discount if you ride your bike there, but see their website for details.
I think this is great and the range of topics will be huge, ranging from green building and eco-shopping to socially responsible investing. They are anticipating an audience of 30,000, so expect crowds! 150 visionary speakers (including Greg Nickels), 300 local and national green businesses, and community groups all coming together for the first time to celebrate green development.
Let's go support this event so that it will become an annual event! Props to Seattle for catching up to D.C, San Francisco, and Chicago:)