DIY Wishlist: A Patio Shade Sail

It's suddenly hot outside. Which has me trying to figure out how to DIY a little shade for the patio and love the idea of a shade sail. I've been looking around for inspiration and love the ones pictured here:

Sails like those from Coolaroo can be purchased for as little as $90. Find DIY installation tips and custom shades at Custom Shade Sails. And see a wonderful DIY from start to finish by this Flickr member.

Do any readers out there have a shade sail in their outdoor space? How do you like it?

Images: Coolaroo, Practical Home and Garden, Tom Spencer/Soul of the Garden, Coolaroo