I was messing around with displacement maps in After Effects and you can get some cool effects. I found that with some expressions and gradients that move over time can make for some pretty cool looking fire. Add to that some particle smoke and little bits dropping off and you got your self a cool looking animation. I found a great tutorial from Andrew Kramer on http://www.videocopilot.net that shows you how to do this effect and then use it on any objects with some tweaks. Enjoy!

Fun with Displacement Maps