I have a Fitbit One and a heart rate monitor. They do very different things.

The HRM monitors your heart rate during exercise and calculates the calories you burned during your workout -- only during your workout. (Note that it is not considered to be accurate for weight lifting, yoga and other non-cardio type of activities). Most people buy these for the calorie burn. I'm an odd ball. I got mine to monitor my heart rate. :-)

The Fitbit One uses a formula (based on your age & weight) to estimate how many calories you burn all day. This base range can be achieved by wearing it or leaving it on your dresser. In addition, it estimates how many additional calories you burn by using a device called an accelerometer that measures your body movement. It counts your steps, knows if you've been walking slowly or quickly and is supposed to know if you've gone up a flight of stairs (but I've found the stair thing to be somewhat inaccurate).

I don't think there is any wearable device that can exactly measure our calorie burn, our sleep, flights of stairs, etc. But in MY case -- someone whose exercise consists mainly of walking 7,000 steps a day -- I've found the Fitbit One to be a really good estimator. Even better, it's a wonderful motivator!

Some people say the Bodymedia is more accurate because it takes into account body temp, skin moisture, etc. But I am glad that I did not go with the Bodymedia. Wearing it on my upper arm all day would be a problem.

The Fitbit is small, discreet. The biggest complaint I hear is that people lose them. I keep mine clipped to the inside of waistband of my panties. That way, if it falls out of its little holder then it can't fall to the ground. I think this also minimizes the chance that it will end up going through the wash after a quick clothing change.

Also, the Bodymedia charges for its website. The Fitbit is free. Without the Bodymedia website or an extra watch-like purchase, you can't read the day's calorie burn. With the Fitbit One, everything is on the face of the tracker at the click of a button so you can check your progress throughout the day. (note: it does reset itself at midnight)

Just know that the Fitbit does not sync with all phones. If your phone is not on the list, your Fitbit won't get to the Fitbit site or MFP until you get home to your computer. Personally, I don't find this to be a problem since I already know how many calories I want to eat and do not base it off my Fitbit burn.

Let me know what you think and where you can get a good one without spending a fortune! :-)

I got my Polar FT4 on sale at Sears.com for $45.99. Shortly after, they ran out of stock and then the price jumped back to $89.99. I

I did notice that Amazon has it on sale for $59.99. It's the ugly bronze one (like mine), but for the price I did not complain.

http://www.amazon.com/Polar-Heart-Monitor-Watch-Bronze/dp/B001U0OFD2/ref=sr_1_4?ie=UTF8&qid=1366931886&sr=8-4&keywords=Polar+FT4

The cute pink & purple one is down to $66.27 at Amazon:
http://www.amazon.com/Polar-Heart-Rate-Monitor-Purple/dp/B005M1P85O/ref=sr_1_1?ie=UTF8&qid=1366932063&sr=8-1&keywords=Polar+FT4

There are others listed, but I tend to look for the items sold by Amazon, so I know there won't be a hassle if I need to return it.

Love my fitbit one and never leave home without it. I've been careful not to wash it though. :happy:

I like the friendly compatition that happens on there with your friends you can see their steps and try to out do them or encourage them or chat with them.

If anyone would like to be "fitbit friends" message me, or send me your link! I just got my flex this week.

I got my Polar FT4 on sale at Sears.com for $45.99. Shortly after, they ran out of stock and then the price jumped back to $89.99. I

I did notice that Amazon has it on sale for $59.99. It's the ugly bronze one (like mine), but for the price I did not complain.

http://www.amazon.com/Polar-Heart-Monitor-Watch-Bronze/dp/B001U0OFD2/ref=sr_1_4?ie=UTF8&qid=1366931886&sr=8-4&keywords=Polar+FT4

The cute pink & purple one is down to $66.27 at Amazon:
http://www.amazon.com/Polar-Heart-Rate-Monitor-Purple/dp/B005M1P85O/ref=sr_1_1?ie=UTF8&qid=1366932063&sr=8-1&keywords=Polar+FT4

There are others listed, but I tend to look for the items sold by Amazon, so I know there won't be a hassle if I need to return it.

The one you have is also on sale at HeartRateMonitors.com for 62.88 with 5% off and free shipping. Not sure about their returns policy! (Coupon code MFP5.)

Today is my first day with my BodyMedia Fit Link....and so far so good! I am still trying to figure it out....like I've never used blue tooth before, so I don't know how to synch it up with my yet. I do see that it estimates my calories burned at a much lower rate than MyFitnessPal. It is too early for me to tell you if I like it or not. Time will tell. I did earn the money to pay for it through losing weight doing DietBets. I do want to get an HRM eventually. It was really a toss up for me between BodyMedia and FitBit. FitBit is less expensive, but I thought I might lose it. It's harder to lose something that is strapped to your arm. I would love to try one out though!

Love my Fitbit. I attach it to my pocket at the beginning of the day and off I go. It encourages me to walk more because of my 5 miles per day goal. One day I even made it to 7 miles!!