Where i can see different types of innovative poster designs?



Answer:
Since you're asking your question in the "Advertising & Marketing" section I assume you mean "advertising posters".

Here are just a few sites -

http://www.globaldesigns.com/posters.htm...
http://gpn.unl.edu/cml/cml_product.asp?c...
http://www.wisconsinhistory.org/artofthe...
http://www.art.com/asp/display-asp/_/id-...
http://webpages.marshall.edu/~bennett7/g...
http://www.charlesmichaelgallery.com/vin...
http://www.francofolie.com/
http://www.poster.com.pl/poster-6.htm...
http://www.chisholm-poster.com/...
http://www.uprr.com/aboutup/photos/adver...
http://www.vintageposterworks.com/...