On SW Salmon between 1st and 2nd, in Portland, we spotted this free charging station for electric vehicles.
The cord for the electric zapcar simply plugs into what we think of as the gas cap.
There was a second car that may have been a conversion from gas to electric, it apparently had its batteries in the trunk.

Apparently electric vehicle can pull up to the curb, plug in, and charge up. This filling station is courtesy of Portland General Electric. It is also illegal to park a gas powered car in the station spots at any time.