On my last visit to London, I had a few hours spare and went to the Magnificent Maps exhibition at the British Library, just because it happened to be on my way. Found it really interesting in the way it shows the different ways in which maps have been used in different contexts - each represented by a room of the venue, e.g. the audience chamber, the bedchamber, the merchant's house, etc.
I actually tend to put maps on my walls as well, have a huge pseudo-realistic view of Europe on display, and an aerial photograph of Oxford (kind of a map as well). Sad though that satnavs and google maps will drive all map makers out of business, so I'm not sure whether there will be any maps from the 21st century to feature in future exhibitions.
Magnificent Maps continues until Sept.19