You can support local charities, positively affect the environment and save money--all in a trip to your local thrift store.
Mine is Savers of Orem. When I shop there (often), a portion of what I spend supports the Friends of National Multiple Sclerosis Society of Utah. That's good. Reducing solid waste? Great. Finding a mint-condition Paul Simon LP for 75¢? Now that's what I'm talking about.
Bonus: you can empty your closet's contents and fill it up again at the same place. Last I checked, you can't leave a box of sweaters at Old Navy's back door before buying a new one.
Where/how/when you spend your money matters. MaKe iT COuNT.