Ginko nuts are reputed to be very healthy, stimulating the brain, preventing Alzheimer's and other degenerative brain diseases. The leaves also can be made into a soothing skin salve. We don't know whether these claims have any basis, but we do know that roasted ginko nuts go awesome with a cup of oolong tea.
So if you notice a tree with fan shaped leaves, and plum shaped fruits which smell like dog feces it's probably a ginko. Only the female trees bear fruit, and they need to be in proximity to a male ginko to make the nuts. Ginkos are considered to be a "living fossil" because they have been thriving for tens of thousands of years in their current form.
A note of caution: Ginko seeds contain urushiol, which is the same chemical that causes poison oak, ivy and sumac to create an allergic reaction, and skin rash. Wear gloves and protect your skin when handling the fruit!
If you know of ginko tree in your neighborhood, you may skip this step. Otherwise, locate ginko tress in your neighborhood by going to Public Trees Map at the Neighborhood Fruit website. Put your zipcode and distance (ex. 94110 and 1) and search. Take note of the tree addresses and get ready for your adventure!