If you really are dumb enough to send real cardboard Christmas cards (I’m still trying to convince my family not to), then shame on you. Bad! Meanwhile for the rest of us, try a video card with Skype. You pick a card, record your own greeting and send it.
There’s a Facebook app and there’s also a standalone Skype version which lets you send messages to people who don’t use Facebook. In the standalone version, people can also embed their video messages on their blogs, as below.
Have a good one!