Basically, what Gen said.

And Zandor, you're mistaken. I was skeptical too until I tried it. I've had cuttings survive in the fridge for 8 weeks, without changing water, blowing in co2, or doing anything else. I suppose you may get them to survive longer if you really took care of them.

After 8 weeks they were getting a little slimey, and only about 45% survived through rooting. Do not keep them an area of the fridge that partially freezes things, if yours is that cold. I kept mine in little tupperware containers with the cuttings submerged in PH adjusted tap water.

You want them as cold as possible without freezing. This will slow down their metabolism and almost put them into hybernation.