Carboy Heater

So its winter, and I'm trying to make a batch of ale, and I like the cold, so I keep my house at about 57 degrees, (yeah I could make a lager) but I'm sticking with ale for now.

But so long story short is, I had seen a carboy heater (brew belt etc) in my local Homebrew store, thats all fine and dandy, but they are only supposed to be used for up to 8 days, plus, I got an electric blanket for christmas last year, and I figured that I might turn it into a carboy heater...

So I was wondering if anyone else had taken an old electric blanket to use on a low setting to maintain a temperature, or if someone had maybe tricked out a blanket, because as it stands now I'd probably just set it at a 2-3 and leave it for a week or 2.

Thanks in advanced

I use the small heating pads from Walmart, $10. I disable the auto-shutoff and set them on LOW, controlled by an aquarium heater.

I've had a brewbelt running on a carboy/temp controller for about a month now. No problems.

I use a small 8 watt reptile heating pad, and wrap a jacket around the carboy and it holds steady temp.