Are you a huge fan of Juneberries or mulberries and upset that you can rarely find them at a farmer's market, and never at a grocery store? There is a great database called Falling Fruit with a Google map showing where every public or semi-public fruit tree is. Type in an address, or share your location, and then search to see where gingko nuts or even an apricot tree can be found. Feel free to add to it. The Oak Park Forestry Division seems to have pretty good coverage of what can be found on the far West Side.