Actually, most (if not all) squash blossoms are edible. I particularly like to eat the summer squash blossoms when they have a miniature squash attched.
Squash blossoms are delightfull tasty, but don't limit yourself to only squash flowers.
As you know, cauliflower, artichokes, and broccoli are flowers (actually flower buds) commonly eaten. There are many, many more flowers that can add color and flavor to a variety of dishes. Rose petals, Nasturtium, violas..... the list is long.
A quick Google search turned up this site you might find interesting.
oldcot, the link for edible flowers is great !!! :P
I serve flowers lunches in my restaurant, they are quite well known, and this link you metioned is perfect for new ideas! Thank-you!