Through May 4, 2009, you can send a FREE 5x7 paper card from Hallmark.com for any occasion! While this promotion was specifically created for Mother's Day, you do not have to send a Mother's Day card.
Go here and create a card up to $3.49 in value (excludes cards with sound and invitation/announcement cards). Personalize your card and add photos if you'd like. Then, when you go to check out enter the code CARD4MOM. You'll get the card for free plus shipping will be free as well.
If you don't have anyone you need to send a card to in the next few weeks, you can even order a card for a future date and have it scheduled to be sent then. How cool would that be for people like me who always forget to send cards until the event is almost past?!