Cheap Gas on Google Maps

http://www.ahding.com/cheapgas/

From Lifehacker:

In a heavenly marriage of Gas Buddy and Google Maps, the developer at Ahding.com created a map of the places to find cheap gas near you. Choose your city, filter by diesel or regular unleaded gas, and see prices right on the map.

Cheap gas [Ahding.com via Google Tutor & Advisor]