In your FiveYearItch.com signup, did you specify the crucial requirements that you need to succeed: Top colleagues, flat hierarchy, passing the Joel Test? If so, and if they can guarantee you that, go for it!
Yes, absolutely, I specified those things and more in my FiveYearItch profile, and at least on that score it's been good -- some employers apparently don't want to contact me if they think I'm asking for too much :-) but the ones who do make offers are all quite serious.