Creating flame textures

I am using the game engine to make a quick demo.

I would like to make some realistic flames, but I lack any decent flame textures. What do you guys use to make nice flame textures?

Also how do you guys usually apply them in blender for realistic flames? I may be able to take the idea and program a similar emitter for real time things.

Check this out… It may come in handy. After checking that out, I found this. I hope you learned a lesson here today.