I've done macro with excessive macro rings or a telephoto/macro lens before... but it was messy and difficult. I'm looking to purchase a macro lens as well as an external macro flash.

http://www.flickr.com/photos/johnhallmen/5946925481/

http://www.flickr.com/photos/gmazza/4511793901/

http://www.flickr.com/photos/flarecreative/4856106379/