These little el cheapo close-up lenses really work great, just don’t stack three or you’ll be wasting your time. I have a nice detailed review here. I used the Hoya 49mm set, which fits my Sony/Minolta 28mm F/2.8, and the Minolta 35-70mm F/4 lenses. I tested them on both but most of the review uses the 35-70mm which has a better macro to start with. Check out the nice close-up I took with the 28mm lens, not bad for a 0.13x reproduction ratio.
Next up is the Sony 28mm F/2.8 review. I’m still plugging away at the new macro page, be patient.