So earlier this year I started to play around with a site/service called Night Cafe Studio, which is essentially a super easy to use web GUI for style transfer. It allows you to upload a source image and one or more target images to transfer the style from. The intended use and best results come from using photos of objects and landscapes and running them against some sort of painting, drawing, or other artwork. However, other mediums such as smoke, raw beef, pie, and classified documents work quite well and produce interesting results too.
You can check out more images at Artificial Imagery.