Green as a thistle.com: You shoes, you lose
Although I recycle stuff, I tend not to worry much about the environment. Nevertheless, if worrying about the environment gets people to take their shoes off at the door, I am all for environmentalism.
This blog recommends that you adopt a shoes-off policy in your home, not just for family but also for guests and other visitors. Socks, slippers and bare feet are fine indoors, but not shoes. Just say NO to shoes in your house!