Beau-Coup specializes in wedding party favors, bridal favors, and general party favors. However, they also offer some Save the Date magnets and also Save the Date mint tins. In terms of magnets they offer standard Save the Date magnets and they also can create a customized caricature Save the date magnet that uses a picture that you send them.
If you want something really unique, consider the Save the Date mint tins from Beau-coup. These allow you to remind your friends and family of your special day and share with them some delicious mints. While I really like this idea please note that it may cost you more in terms of postage to mail mint tins vs. standard cards or magnets.