Well went to rack my beer yesterday and found out my heating pad is no longer heating. I thought about just buying another or getting a brew belt, but after thinking about it I realized that they both could be a waste of money.
Right now I'm fermenting in a fridge with a 2 stage controller, but I'm going to expand to a fermentation cabinet (simmilar to http://www.wortomatic.com/articles/Knews-Hound-Builds-the-Beast). So with that in mind what would be the best long term way to add heat?

One possible way is to put the fermenter into a tub of water, use an aquarium heater and a submersible aquarium pump to circulate the water to keep the temp consistent. Crank the thermostat all the way up (always on) on the heater and use your two-stage controller to run the heater. Leave the pump always on. You can get those pieces of equipment cheap on eBay.
My $0.02 -CH

I have had great success with fermentation temp control using the More-Beer 2 stage controler with the electric fermentation heater that is a mylar printed heater that get taped around the carboy or pail. Set the cooling and the heating to the same temp, set the differential for both to 1 degree. It holds the temp steady. I cover the temp sensor with a fitted foam insulation that presses the sensor against the carboy. The heater warms slowly so it is important to get the wort very close to ferment temp. The heater cleans up easily after blow outs, etc.

I spent less than 10 bucks and put a lightbulb in a paint can - tore up an extension cord and hooked it up to my two stage temperature controller ($20 Chinease cheapo on eBay) - all in small freezer. Worked out great for me so far.