I just got a PM from photolady, sorry I wasn't around.
I've been using a binocular lens for macro work since 2010 or so. I took the objective lens off a pair of junk binoculars, it fits snugly on a 50mm lens with 49mm filter ring, and works quite well. Focusing distance is rather close, 6 inches or so, and image quality is very good. Here's an example, if i can get the new Flickr link to work...
I use extension tubes a lot too, with a 135mm lens. You can also get teleconverters fairly cheap and remove the glass, instant extension tube.
I can't find my picture of the binocular lens rig ready to go, but it just slips onto the front of the lens, the rubber covering grips well enough it rarely falls off. As with any form of macro photography the depth of field is pretty slim, otherwise it's about the same as shooting without it, but I have to use a card to reflect the flash downward if I use flash.