I did my Master's thesis on enhancing bone recovery with whole body vibration (which it did work in our animal model). There is more and more solid evidence coming out as far as weight loss, fat loss, improvements in muscle strength and muscle mass, flexibility, enhancing functionality in the elderly and special populations, and particularly for enhancing bone mass. We're talking about as little as 10 min. a day (30-90 Hz. and low amplitude) could have an impact on your health. I'd suggest doing a Google and Pubmed on Clinton Rubin (Rubin C or Rubin CT) at SUNY Stoney Brook.
The only problem is there are lots of companies coming out with smaller vibration platforms for consumer-use that may be dangerous (~amplitude/how much it oscillates vertically is too high, which has contraindications). The particular model we used for our studies is by Pneumex (Pneu-Vibe Pro:
http://www.pneumex.com/pneu-vibe.htm
)-- we actually tested it ourselves to make sure it was at the right frequency and amplitude for our studies. We have two models by Pneumex at around $12,000 each-- they're larger and more appropriate for clinical use.