Some states regulate the transportation of plants and require that you declare any plants you bring across their borders to prevent plant pests and diseases from being spread to the state. AeroGarden hydroponic planters include built-in grow lights and come in a variety of colors and sizes.
If you travel in climates where the temperatures stay above freezing you can easily grow plants outdoors in containers. Small pots or planters can be stored in a truck bed or in the shower during transport.
Perhaps one of these ideas can help solve the problems of weight and ease of transportation RV owners face when trying to grow larger quantities of plants or vegetables while moving from place to place.