Silhouettes lend themselves beautifully to all kinds of paper goods. I love making them into personalized cards. I prefer to leave the silhouettes in black, and use some color for the type. A colored envelope is a nice touch. I'm a big fan of thank you notes, and personalized ones with Bee's silhouette were perfect for Bee's birthday party.
A family of silhouettes makes a nice notecard. I'm hoping to send a set of these to my brothers and sisters when their birthdays come around. (Get ready, little brother!)
A cute anniversary card can be made by printing two silhouettes on a gatefold card. This one opens up to a heart that says "Happy Anniversary!"