I was thinking about tinting also.
They make a "low-e" coating that applies similar to tinting. The "e" stands for emissivity (sp?), wich is the ability to transmit heat through the glass. They stop the heat more than the light. Keeep it out in the summer and in during the winter.
Real "low-e" coatings are nearly invisible. But the aftermarket styles usually have some tint to them. Places like RealGoods (
www.realgoods.com) or any solar living catalog should have it.
Let me know how it works...