Mac OSX bases much of its interface on Adobe’s PDF format and opportunities to use and make PDF files are ubiquitous.
My favorite PDF trick helps me create an archived digital receipt every time I make a purchase online.
You now have a single location for all your receipts and account info . If you’re really cool, you might want to create sub-directories for each type of item (“Receipts,” “Accounts,” “MySQL Setups,” “Affiliate Reports,” etc.