Greeting cards are a great way to tell someone you care, express gratitude or send out holiday tidings, but let's face it: as soon as the occasion has passed, most cards just end up taking up space and adding to clutter in your home. Instead of just throwing the cards away, however, there are tons of ways that you can reuse or recycle them. If the card is very meaningful to you or you just want to remember who sent you what, you can always scan cards into your computer before you use them for another purpose.
Check out some of these great ideas from wikiHow:
Make Gift Tags for Presents: cut your old greeting cards into smaller sizes (in strips or rectangular pieces), fold them down the middle and write the "to" and "from."
Make a Gift Pouch: reuse old cards to make a gift pouch for small gifts like jewelry, CDs, perfume, etc.
Make a Bookmark: cut the card into strips that are about 1 1/2 inches wide and 6 inches long. Punch a hole near one end and add a tassel. You can give these away in books that you give as gifts. Check out this great tutorial to learn how to make your own bookmark tassels.