Can you measure radius on Google Maps? Drawing a circle with a certain radius around a fixed point could, for instance, show you all the parks within 3.1 miles (5km) of your house.

Find the map’s scale, extend your compass to cover 5km, stick the pin in your home address and give that bad boy a 360 degree twirl. That’s your radius. Have fun, and stay safe.

Many paid search programs offer a way to geotarget your search ads. Google, Yahoo and Microsoft allow you to specify a radius in X miles, for how wide or small you want to target a specific location.