I hate keeping physical things anymore. I love Evernote. I always have felt a twinge of guilt about reading then discarding cards. From Christmas to Birthday to Arbor Day cards, it is very nice that people thought to send things, but I really don’t want to keep them around.
Solution? Evernote + Scansnap. Now I just scan the card into a notebook and toss it out. I actually keep and can look back at them if so desired, but don’t have the physical clutter.
Bonus tip, scan the envelope too and you have a good reference for mailing addresses.