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.

Flash and shot horizontally, the grass getting black by contrast (this has been shot in the sun, the background has been slightly darkened in post by playing with contrast and blacks sliders in Adobe Lightroom)

Flash and camera from below (flash held under the camera)

Creating high contrast with the flash. Here again, the background has been darkened a bit in post production (with Adobe Lightroom)
What are the advantages of flash here? You can create a high contrast scene, for instance, the flowers on a dark background: by having more light on the flowers (much more light), the background becomes dark by contrast, even under the sun. You can also lower contrast (flowers shot from below, by adding light to the flowers, you reduce the contrast with the sky. Without the flash the sky would not have been blue but very light blue or white or the flowers would have been dark (the contrast between the sunny sky and the flowers being too high).
And now something different:

Flash from the left to get the colored shadow. D40x, SB-600 with cable, 60mm AF-S micro
Guy Van Hooveld is an executive in the IT sector and also a freelance photographer. He is mainly specialized in industrial, corporate and event photography.
He also owns and manages the photography wiki (http://www.techniphoto.com/wiki), a site publishing general information about photography, reviews (contributors are welcome BTW). He also has experience in other areas like sports, product, landscape and wildlife photography.
Company: Guy Van Hooveld Photography
Webiste: http://www.techniphoto.com
Blog: http://guyvanhooveld.blogspot.com
Twitter: http://twitter.com/photographywiki
Facebook: http://www.facebook.com/pages/Photography-Wiki/180789648015
Photo/Video Credits: © 2010 Guy Van Hooveld
Here’s how you can share your tips, techniques and tutorials on CurrentPhotographer.com
–
*The Current Photographer website contains links to our affiliate partners. Purchasing products and services through these links helps support our efforts to bring you the quality information you love and there’s no additional cost to you.
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …
RT @TrevorCurrent: Shooting/Lighting Tip: How to Use Your Flash Outdoors for Some Interesting Effects. https://currentphotographer.com/how-to-us… #photogra …