StreetComplete makes contributing to OpenStreetMap easy and fun by turning contributions into "quests" on a map for you to complete. No personal information is required, just create an OpenStreetMap account, and start contributing directly in your area!

I tried this out myself, and it is truly fantastic! I had never heard of it, and I'm sure many of you haven't either, so spread the word!

Tip: When entering buildings to ask questions (opening hours, etc.) be ready to explain what OpenStreetMap is :)