Yeah, at-will employment can be bad when an employer fires someone for no apparent reason, yet it can also be good when you get sick of the job and can literally just walk off and tell them exactly how you feel without worry of repercussion. I only give employers a two week notice when leaving if I think there is a possibility I would need to work there again in the future. Otherwise I have walked off more jobs after getting fed up with their corporate BS.
IgnoredOne,
Not that it helps your situation, but do keep in mind that you don't have to tell other possible employers that you were fired and legally, your previous company can't really tell them either. All they can basically say if someone calls is, "Yes that person used to work for us." My understanding is that any other information could lead to legal issues regarding slander. (I may be wrong here, but I have never had any issues myself with this.)