You can almost immediately tell Orton modified images. They have a dreamy look to them, with soft blurs, hard edges and are well saturated. Michael Orton developed this technique in slide film. Here is a excellent page describing how you can make your own Orton modified images. There is a entire flickr group dedicated to this technique as well. The video below shows a modified 3 layer Orton technique using Photoshop and layers. More discussion about the video by the author can be found through this flickr discussion thread.