I recently accepted a new job which I will be starting at after Thanksgiving. If you had asked me if I would be changing jobs a few weeks ago, I would have said you were crazy.
Reason being, was that I really wasn't looking, but someone noticed my resume on Monster.com and sent me an e-mail that caught my eye. I decided to check it out and after a lot of thought, accepted their offer.
My biggest worry wasn't about being able to do the job but the timing of it all. One of my coworkers is at the last stages of building a house and taking a well deserved vacation soon. Anytime he is not there, my workload doubles and anytime I'm not there, his workload doubles. I also consider him a good friend so I didn't want to have him go on vacation and come back to work with no one there to help out. It bothered me the whole weekend before handing in my 3 week notice.
I did 3 weeks so that he could still go on vacation and have me there for another week to help out. The new place was cool with that, so I set it up that way. Overall things have worked out pretty well.