"temporary" structures
 

I just saw this
http://www.oobject.com/category/9-pe...ry-structures/

I think you get the idea:

http://farm3.static.flickr.com/2534/...49f7d680_z.jpg
http://www.flickr.com/photos/fromthenorth/3985400226/

Hard to think of many beyond those examples. I guess the archetypal temporary structure is the wartime Nissan Hut:

http://www.selfsufficientish.com/for...le.php?id=1083
http://www.selfsufficientish.com/for...p?f=34&t=18327
Self-sufficientish

http://farm5.static.flickr.com/4135/...196f88e8_z.jpg
http://www.flickr.com/photos/ilike/4...n/photostream/
I Like, Flickr, Some rights reserved

I went round Winchester Cathedral last year - there an oak structure there that is part of the inside of the cathedral, which was put up around 1500 when the cathedral was being reworked, and it was supposed to be replaced with stone. However, the money ran out, and the 'temporary' wooden structure has stayed in place for the last 500 years.