This might sound strange but it is possible to get interesting effects with a flash on a very sunny day. The classical application is to use fill flash to get the proper exposure in the shadows, but there are other possibilities as well.
I decided to experiment with cheap gear, so that anyone could give it a try: I am still using my simple Nikon D40x on a regular basis to have some fun… I added a flash (a simple Nikon SB-600, but any other similar or better flash will do, like the SB-800 or the more recent SB-900) I also (re)discovered the use of an iTTL flash cable conecting the flash to camera body hotshoe to flash from various angles with cameras without the wireless possibilities of CLS (and without the delay introduced by CLS, the wireless Creative Lighting System by Nikon)
Here are a few examples in the sun, using the 60mm AF-S micro lens, diaphragm closed down to f13-16, with a touch of flash.

Flash from above just to show the flowers.







Photographing weddings for a living is fun. The way I see it, I get to do what I love. I get to go to a kick-ass party and get free food at the same time! This is the life! What can possibly be bad?