There are a lot of fitness gadgets out there, some of them work, some don't.
One gadget that gets my stamp of approval is the bodybugg from Apex Fitness. Basically the bodybugg is an armband device that you wear on your triceps throughout the day. This smart little bugg measures how many calories you use in a day based on some very scientific calculations of body heat, motion, gravity and skin response. It gets way cooler, so
After you go about your day, you then upload all the information from the bugg to your computer and watch the magic happen. You'll be able to see charts showing how many calories you burned and when, to the hour. I would look at it and say, "Oh, that is when I walked to the bus, and oh, that's when I had a meeting. Look, that's when I went to the gym!" After that, you enter your calorie intake information (i.e. what you ate). This part can take a little bit of time but the database on bodybugg.com has a lot of food uploaded already, so most stuff is instantly recognized. Once you do that, you'll be able to see if you're at a surplus of calories (who's up for a quick walk around the neighborhood before dinner?) or if you're at a loss of calories (did someone say ice cream sundaes?) for the day.
I especially loved that the bodybugg is also a pedometer, so I was able to track my steps -- If I hadn't made it to 10,000 by dinner; I was doing a few laps around my house during American Idol. While my husband was less than thrilled that my Type A personality was being fed like a wildfire, I was thrilled. The only things I did not love about the bugg were that it hardly matched my outfits and that it only works with a PC (as of now at least). The pros definitely outweigh the cons though, so check it out on bodybugg.com.
This thing is addictive, but for good reason, never before have I been able to see (with such detail) my personal input and output of calories. The bugg does not come cheap; it's $399 for the bodybugg, a 3-month membership and two private phone sessions (with very helpful coaches, might I add). After that the membership is monthly (or yearly, depending how hooked you are). I would highly recommend this for anyone trying to lose weight because it really lays it all out there, making it easy: To lose weight you need to consume less calories than you use, plain and simple.