AKVIS AirBrush is a commercial tool which transforms digital photos into airbrushed works of art.
You've probably seen other "photo > artwork" tools before, but usually they're trying to emulate paintings, maybe sketches, and this means they lose a lot of detail. AKVIS AirBrush by default preserves much more of the original photo, while still giving it a very eye-catching look. Check the grab for an example (there are more on the product and screenshots page, and you'll find a detailed description of the technique here).
You don't need any artistic ability to create a masterpiece. Just open an image, drag a few sliders (Detail, Sharpness, Smudging, Lightness and more), perhaps choose a colour mode, and the preview window updates to show the results.
Extras include a watermarking tool and batch processing feature, and the results can be saved as images, or shared directly via Twitter, Flickr, Google+ or Dropbox.
Please note, there are multiple editions of AirBrush available, and the prices range from $49 to $89. There's a comparison here.
AKVIS AirBrush isn't cheap, but it can produce spectacular results, and the trial edition is generous: you can produce as many images as you like with no watermarks or other restrictions.