i havent tried it though i have read a few articles etc on it. its basically a healthier version of the atkins diet (more carbs, healthy fats etc). personally instead of going on a diet such as the south beach why not just follow a few simple basic guidelines.
+ avoid foods high in sugar (ie. cereal bars, sweets, fizzy drinks)
+ avoid foods high in saturated fat (although all fat isnt bad mono + poly fats are good fats and should be eaten on a regular basis - can be found in oily fish like salmon, nuts, seeds etc)
+ drink plenty of water
+ instead of eating 3 big meals it would be better to break down these meals into 5 smaller meals (you will feel less hungry and you can digest far better)
+ at each of the 5 meals have a good combination of healthy fats, low gi carbs like wholemeal foods or pasta, and protein.
+ eat lots of fruit and veg
+ dont become obsessed with ur diet just follow the few simple rules and exercise regularly.