A quick warning on E-card sites. Some of these are simply fronts used to build mailing lists that are then sold to spammers. Yes, they do send the card, but they also record the e-mail addrsss the card was sent to and place it on the list. Not all e-card sites do this, but its best to stick with ones like hallmark.com that are known to be reputable and will not sell the address of your friend or relative.
Check the privacy statement on the site. If it doesn't have one, or the statement doesn't specifically say they won't sell the addresses they acquire, stay away. After all, nothing says Merry Christmas like a big pile of unwanted spam.