I have almost put my plants into hybernation by lighting with flouros and lowering the temps.

Other than the stuff mentioned above, you could move your lights far away and lower the temps as close to freezing as possible without freezing. I've never tried this with growing plants, but I've hybernated cuttings in the refregerator for 8 weeks.

Do you have an old air conditioner around? You can use mine out in the shed.