I travel a lot. As a musician I often find myself looking for information late at night and/or in the middle of nowhere, when asking someone for help is seldom an option. Therefore, I rely a lot on Google Maps and the information it provides. As a consequence, I try to make it a habit to check whether the place I am visiting is on Google Maps and the provided information is correct.
I look for anything I would find useful: hotels, live music clubs, bus stop, train station, petrol station, shops. If a place is missing, I add it. If anything - i.e. location, hours, phone number, website - is wrong or not provided, I suggest an edit.
It is a simple way to help others, and my personal thank-you note to whoever provided contributions that were extremely useful to me.