One of our readers, Susan Jacobs, sent us the address of a web site that which gives you a 360 degree view of every category of cabins and every venue and public area of the ships of most of the major cruise lines. This is actually a marketing site to sell this new technology. It will soon be updated so you will be able to view hotel rooms, vacation sites and homes that are listed in the real estate market. Take our word for it, you haven’t seen anything like it.
Also worth noting that Aida, A'Rosa, Costa, HAL (AMSTERDAM and VEENDAM only), Peter Deilmann (DEUTSCHLAND only), Princess (some ships only), and Star Clippers have their own virtual tours on their own sites. Those are the only others I can think of, aside from the ones mentioned above...