We have a small 9x9x9 one over our patio outside our kitchen. I love the way it looks, but should have gone with a larger size for more shade. The roof elevations around the patio are very low and did not allow for a large sail. Properly attached, they can handle substantial winds. Check out some of the pictures of the multiple sails set at different elevations. Very cool.

Thank you tcian :) Do you take yours down in the winter?
Do you know of a good website that shows photos?

Yes, I take it down in the winter. (Michigan) I think I went to Shadesail.com for ideas. I used stainless steel chains with turnbuckles from Lowes for the installation, but I like the look of stainless cables better, but more expensive.

I have shade sails over my koi ponds. They are fantastic! They have been up for 5 summers now and show no signs of wear or discoloration at all. I have them attached to 3" steel pipes. I usually take them down in the winter because I worried about how they would handle snow or ice. This year, I forgot. And we had snow. By the time I remembered, there was 10" of snow on the sails. They hung down very low, but it did not damage them. I think the cables slipped instead! At any rate, the snow melted and I tightened the cables back up.....they are perfect! They also withstand pretty strong gusts. Mine are Coolaroo brand and came from Ebay.

I bought two for my house from www.mightycovers.com and just love them. I got mine made of Commercial 95 fabric and they came in a variety of colors.

Here is a link that might be useful: Shade Sails : Sun Shades