Exhibition posters (or indeed, theatre or film posters) are always worth keeping an eye open for - the older they are, the cooler they look. Put it in a cheap frame (or visit your local framer*) and you will immediately have a handsome piece of cultural history for your wall.
....And if your house is a bit rough and around the edges, work that bohemian look and pin straight to the wall like Jean Seberg in 'Breathless' (1960).
* My framer is retired from a notable London gallery, now he makes beautiful frames in his home studio and charges the most reasonable fares for frames that will last a lifetime.