Displaying Crafts

I am constantly torn between the following dichotomy: wanting to declutter my home and throw out every project the girls make versus wanting to honor their hard work and displaying it.  The girls will sometimes hang their drawings up on various doors and walls throughout the house.  After a few days, I will take them down and throw them out at night after the girls have gone to sleep. 

One evening while I was cleaning the kitchen Sabrina said "Look, Mommy, I'm done."  Without thinking, I picked her painting up, crumpled it in my hands, and threw it in the trash can.  She started balling, pointing to the trash can, saying "You threw it out."  Oops, what a bad mommy.  I then had to take her painting out of the trash, uncrumple it, and act like it was a Picasso.   

So, we have a string hung up in our foyer that we hang the more special projects up for about a week.  We still have tons of stuff which I throw out every night, but I am careful not to do it in front of them.  Here's our foyer display area:

The girls frequently take visitors to the foyer and point out their projects.  How do you display your kids' artwork? And for how long?