Postalz is an online service that lets you communicate with friends and family using postcards.
Postalz is a cool attempt to apply the web2.0 tech to greeting cards, an area mostly neglected by new technologies. Using Postalz, you can create postcards with text, art, photo and video and exchange them privately or publicly.
Postalz has made a good use of AJAX and overall, the product is a neat implementation and has built a cool platform that enables users to explore personalized + rich media cards.
As far as business case is concerned, it all depends on how funky user community they can actually build.
Give Postalz a spin and share your comments. Will you use the product to create personalized greeting cards?