Window Sun Shades

[TMerrell]

Looking for ideas on reducing the amount of heat coming through the windows during the hot summers in the south. We were in a campground in Tallahassee, FL this week and saw two SOBs with exterior "SunShade" brand retractable screens on the rear picture window. I also considerd adding some of the film that reduces heat that you can get from Home Depot. I used it on a bedroom in the stick house and it was very effective.

Anyone have experience or thoughts in this area? Thanks.