Too bad the USPS will provide you with the postmark misspelling on demand-- it would have been pretty hot property otherwise. By the way (this is for you, k-man) collectible stamps are a good investment idea in times like these-- especially if you can pay close to what they're worth in the secondary market.
Why? Because they're extremely portable. Part of the Rothschild fortune, and in fact many fortunes, include valuable stamp collections. Because it's almost impossible to tax them, they can be transported easily, or sent as part of letters (the classic mode is to include a valuable stamp under a common stamp as part of a package. You can tuck hudreds of thousands if not millions of dollars between pages of a book.