Aimed at putting the days of calorie cluelessness behind us, Meal Snap is a new app for iPhone that will tell you just how bad that fast food meal you’re about to scarf down really is for you.

The concept of Meal Snap is simple: take a picture of your food, and MealSnap analyzes it and tells you how many calories it contains. It makes it easy to track your daily food intake, and also allows for sharing of your meals (and their calorie count) on Facebook and Twitter.

Meal Snap also contains a built-in calendar feature, so every meal you snap is logged and you can go back in time to see how your eating habits have changed and what you’re eating each day. A potentially great app for dieters, if it works as advertised people watching what they eat will no longer have to check calorie databases and keep hand-written logs. It’s all automated, just snap and go.

Unfortunately, Meal Snap may not be ready for prime time just yet, as its not really working as advertised. While the Meal Snap website says that the calories are detected “auto-magically,” it seems to me like there is a team of people on the other end entering in what they see in your photos. It takes quite a while to return results, and when they do come they can vary drastically.

In an informal test, MobileCrunch found that the same meal returned very different results:

A “Small handful of cashews”, for example, comes back as being anywhere from 150 to 614 calories.

I had similar problems. After almost 10 minutes of calculating, Meal Snap determined that the cookie I took a picture of was 69-103 calories. Submitting the same picture right after resulted in a count of 150-200, but the cookie box itself said each cookie was 75 . The app appears to be close enough in this test, but I can see how there could be problems with a large, complex meal.

Meal Snap is a great idea in theory. The ability to auto-track your calorie intake each day would be awesome if everything worked effortlessly. However, it’s not effortless (yet). Between long processing times for every picture to calorie counts that vary even when the same picture is submitted twice, there are still some bugs to work out. However, I’d still recommend Meal Snap to anyone who is trying to watch what they eat. The calorie counts are rough, but still useful, and having pictures of every meal in a database like this can be inspiring enough to eat better.