I've read one of Buzan's books on memory techniques, and I agree with what some of you say - it's hard work to think of mental images to associate. It DOES work, and quite well - I can still remember a list of 10 items that someone set me as a test around 12 months ago.
But it's too much hard work to use all the time - it takes too long for me to associate the object with the image.
(P.S. - that list was: 1-staples, 2-water, 3-soap, 4-rugby, 5-coke can, 6-chair, 7-sun, 8-radio, 9-ring, 10-cat)