Go figure -- Microsoft's Courier project lives again as an exclusive app on Apple's iPad. FiftyThree, a company that features folks who previously worked on the aforesaid Courier initiative, has just put forth a monumental effort dubbed Paper. The app, which is available for free in the App Store, is a sophisticated sketchbook with a highly unique user interface that's seemingly designed with the budding artist in mind. Put simply, the company feels that this app is "where ideas begin," enabling users to capture mental light bulbs