Wetwall panels

have fitted few different ones over the years
mermaid boards which are marine ply with a laminate finish with different styles,
good quality work well, and easy to install, available from travis perkins.
a plastic interlocking panels called aquabord from a company called IPSL,
also another good product easy to insall and very good price from www.bcspanels.com tel 01207 270096
have just fitted a complete bathroom out with a product called lustrolite looks great but a real pain to install,
not to be tried by the faint hearted a pain to cut plus prep work,
hope this helps or the good old fashioned way just tile it

 

Not my favourite, lots of prep for a office toilet effect