Mixed feelings on this one. I have lost weight using it but have had to up my carb intake within three days every time because it's made me ill (diarrhea, zero energy, light headed). I've done it in short stints each time, just for a few days to lose a few pounds before a big event. the weight does drop off quickly, but suspect this is partially due to losing water (your mouth is dry all the time and you get ridiculously thirsty - like being diabetic). If you are serious about it then it's essential to buy the book and not just wing it.
I've heard the South Beach Diet is a more up to date version and less extreme.
But I have to say that any diet that cuts out fruit and veg (even for just a couple of weeks) is dangerous.
I wouldn't consider it as a long-term plan because God knows what effect doing it will have on your body.
Cutting out starchy carbs is a less extreme approach (again for a short-term diet) so perhaps consider trying cutting out bread, pasta and potatoes and switching to brown rice with plenty of lean protein and veg is a better idea.
Sorry I can't give it the big thumbs up, but I know of noone, myself included, who has been able to tolerate the Atkins diet for more than a few days without feeling very ill.