No, not postcards to your favorite actors, but actual electronic post cards you can send into space. These cards are delivered to the ISS, or International Space Station, and more specifically to the members of Expedition 26 who currently live there. Or if that’s too retro for you (I built my first electronic postcard page with a Perl Script batch file that tied an image selector, a text entry GUI, and an email server command string bundle around 1995 or so), you can always opt to Tweet the Astronauts your holiday greetings instead. Contrariwise, if both methods of communicating seem too newfangled and hi-tech for your comfort zone, you can find out when they will be visible in your neighborhood and smile and wave at them while they go passing by. Just understand that while you will have no problem seeing them if the cloud cover is favorable, they will probably only notice you if a camera with a sufficient lens assembly is pointed in exactly the right direction, and that only after they have taken and then examined the image in detail.