Favorite Eco-Friendly Thing To Do {Summer #BlogChallenge}

I do many things that are considered "Eco-friendly", but that's honestly not why I do them.  I do them to save money.  A few of these things are:

1. Cloth Diapers.  Especially since we hope to have more children.  I can use them again on them.
2. Cloth Napkins.  I got tired of spending $10-$20/year on disposable napkins.  A nice perk is, I did not spend any money on the cloth napkins since they were given to us as wedding gifts.
3. Menstrual cups.  Must say, I LOVE it.  If you're considering switching, do it.  TMI Warning: I find I do not leak with menstrual cups like I did with tampons, plus the risk of TSS is reduced.

What "Eco-friendly" things do you do?

Do you do them because they're "Eco-friendly"?