Actually, I think that idea by Grumpy of putting cut mosaics in there is a great one, think it would look really good.
Thanks for the thanks by the way, cheers..!
If you were to do & dab plasterboard to get a flat surface to tile too.
You could finish the top off with a dado rail this will hide the exposed edge which you would still get with mosaics etc ......unless they were as thick as the plasterboard and the thickness of the tiles as well.....