Walls and Ceilings - Ugly fake stone behind woodstove

What can I do about a really ugly fake stone wall behind my wood burning stove? Photo is at
http://www.flickr.com/photos/11663550@N08/1144942892/

It doesn't look too bad in the photo, but when you see it in real life, it's hideous!

Any suggestions for what can be done?

You will have to replace the stone with a fire resistant surface, so whatever you had in mind, make sure it won't burn. You could paint the rock....naaaa. Removing it will require the removal of the stove, and that will require 4 rather stout bubba's, so get the hamburgers ready. It may look more stately to have a regular brick hearth and backstop. More orderly since the grout lines will be uniformly in line, etc.

The first thing to do is to locate the manufacturer's instructions and check the required clearance to the back of the stove - it looks to me like it may have been installed to close to start with,

Removing the stone may happen in the future, but it's not something I can contemplate right now. But I would like to find some way to make it less ugly.

I couldn't find the stove's manufacturer's name, but there's an official-looking metal plate attached to the back that lists the required clearences, and they're spot on.
I was thinking of sort of smooshing on some mortar to smooth it out--sort of like a stuccoed stone wall.
I'm going to leave the stone it's sitting on as is--it just looks like flat sandstone. The stuff around the edge of the base will need to be de-uglified, though, same as the stuff on the back wall.