I've only been on Atkins for a couple of months, but I have religiously tracked my carbs since Day 1. Part of it is that I am Type A and I just feel comfortable doing that! For me it is fun as well (OK, I'm a huge dweeb). I downloaded a program on my Palm Pilot that let's me track calories, carbs, protein, fat and fiber. It's similar to fitday, but I can take my Palm with me wherever I go. I have even been known to enter food items beforehand just to figure out if a meal I'm contemplating eating will fit within my carb allowance! The program allows you to enter your own foods as well (it comes with its own food database, which includes well known restaurants). I've input a lot of my own foods using Corinne Netzer's Food Counter as well as inputting nutritional label info from items at the grocery store.

Counting isn't for everyone, but I know I have a tendency to underestimate what I'm eating, in terms of portion size as well as "forgetting" that ounce of cheese here, tablespoon of cream there, etc. So this helps me stay honest!