yep, I'm on it, I'm taking it in addition to doing a modified version of the atkins plan (uh, sort of, no solids here, just shakes, a little chicken/pork/fish)
eh, I lost 5lbs the first week on it, the side effects are not too bad, but that's because my diet is pretty low in fats already, I had previously been losing 3-4lbs a week on my low carb thing.
I guess this week will be more telling (my second weigh in since starting)
you must take a good multivitamin, at least two hours after a dose of xenical, otherwise you'll lose most of the fat soluble vitamins.