How to get rid of old running shoes in an environmentally friendly way

I have several pairs of old running shoes gathering dust in my closet, because I am hesitant to just throw them away in the trash.

Years ago, I read something about one of the shoe manufacturing companies having some shoe recycling program, so I'm hoping that it caught on - but I can't find anything like that anywhere today.

What do you guys do with your old, worn-down running shoes?