The space saving bathroom, by Design Oddyssey, incorporates shower, basin, WC, cistern and storage in a 1600mm long unit. It has a clean, industrial, sleek design.
Source: Doornob Design Ideas.
For purely functional applications, the stainless steel prison WC and sink by Kent Stainless fulfils the most basic requirements for prison use, along with the usual security and safety features. Without being insulting to Design Oddyssey, I did notice a similarity in the two products!