When most people think of green this week, they are probably thinking of St. Patrick's Day. After all, they are turning the entire Chicago River this shade in cele ation. But more locally, there is a different kind of green event that is soon to occur: the Green Expo at the River Trace Baptist Church this Saturday. Focusing on the planet friendly type of green, this event will highlight environmental issues and help attendees learn how to live more sustainably. You can also pick up a native tree to plant in your yard and grab some home products that you don't have to lock away from your children or household pets. Best of all, it's free. Way to save some green there.