I use a seedling heating mat that I got from a plant nursery, it was under $20 and it works well for getting my belgians up to 72 in the winter (in my house that I don't heat)... I just put the carboy about half on the mat to get to 68 and put it all of the way on to get up to 72... pretty cheap and not very scientific, but it works
This is what I have
http://www.neeps.com/039401.html?produc ... elid=FROOG
