I have used xmas lights in the past to heat the root zone of my citrus plants-just wrap them around the pot.

Has anyone tried "rope" lighting? Does it get warm enough to do the trick? My beef with xmas lights is that they're hard to tape to the pot, the bulbs pop out and break, and they're hard to weild. Rope lighting would be cleaner, obviously no chance of accidentally pulling out a bulb and then misplacing it, probably easier to mount/tape to the pot.