Here are two fun online holiday cards that can be sent without any required registration:
Share A Carol lets you type in an address, lets you decorate the location, and then allows you choose a carol to be sung with it. You can write a message and then share it via Facebook, Twitter or email. Students can post a link to their creation on a student/teacher blog or website.
House Bling is a similar site minus the music.
I’ll be adding both to The Best Places To Learn About Christmas, Hanukkah, & Kwanzaa.
Thanks to Google Maps Mania for the tip.