A few days ago I stumpled upon the Inspiration Portfolio by Leon of theplanninglab.com. He posted a pictural map of his favourite sources of inspiration on his Blog.
I like the idea very mutch - because thinking about your sources of inspiration opens the mind to search for new ones. Therefore I created my own Inspiration Portfolio and a posterous-site to collect and share portfolios around the world: http://ipp.posterous.com/
If you want to share your inspiration portfolio - send a mail to: firstname.lastname@example.org
My Inspiration Portfolio looks like this: