Hahaha.. as I saw the headline and tried the combination i got to see the print-priview and thought... WTF???
Now I get it, private browsing.... since my Opera client is already set up not to create much of an history while browsing and completely deleting it after closing it, I don't really feel a need for it. Although opera has the option to create private tabs as well.
Since I use URL-filters, cookie-white-lists, white-lists for sites where Java and plug-ins are enabled and so one, I don't really use it since i don't see see a purpose in it.
EDIT: I especially love the "blocked-content-feature". I always LOL, when l read a text like "Join now!!!, and get rid of the advertisement...", looking at the site, thinking to myself, Advertisement???...where???