The scale looks like it could have been designed by Jonny Ive as an accessory for an iMac. It's a sleek slab of black glass on top of a base with curved sides, so it appears to be hovering. The display is easy to read and can be adjusted to show your weight in pounds, kilograms, or stones. It uses 4 AAA batteries, so there's no power cable running to the scale. I've found that I get great battery life since the scale shuts itself off after use, then turns itself back on when you step on it.
Setup of the scale was easy when I first did it in December of 2009, but now it's even easier. At the time I set up my scale, you needed to connect it to a computer (Mac, Windows, or Linux) at least once via an included USB cable. The USB connection was used to feed the Wi-Fi network parameters (SSID, password, etc...) to the scale. Now, however, the WiScale app can be used from any iOS device to set up the scale.
In terms of network compatibility, the Withings Scale works on 802.11b/g standards and works perfectly with Apple's AirPort devices as a result. It supports WEP, WPA, and WPA2 security modes, which should keep your curious neighbors from packet-sniffing your weight every morning.
As I noted earlier, sharing your weight -- if you want to do that -- is quite easy. You can set up Twitter tweeting ("Whoa, Steve gained 4 pounds overnight!"), Facebook updates, and there's a widget available for most blogging tools that will display your weight. Although I'm not that open, at least until I lose some weight, it's nice to know that I can use these common methods as a way of shaming myself into losing more weight or letting my friends provide motivation.
But the true power of the Withings Scale is apparent when you see how many iOS apps can actually tap into your weight measurements. By my count, which is probably quite low, you can track your progress in the Daily Burn (free), Runkeeper (free or Pro version for $9.99), iBody ($9.99), Weightbot ($1.99), Fit Orbit (free), and Cal2Go ($3.99) apps. I had purchased the awesome Tapbots Weightbot app before I got my Withings Scale, and I was thrilled when I didn't have to manually enter my weight readings anymore. Withings notes that the scale also works with Microsoft HealthVault and Google Health.
When you stand on the scale, it takes about 20 seconds for it to take your weight and determine your fat content, after which the information is sent off to the Withings site. One thing I noticed is that, if you have two users who are approximately the same weight, the scale has problems determining who is currently standing on it. My wife and I ran into that issue recently; she's doing a great job losing weight, while I'm doing an equally good job maintaining my current high weight, so on the occasions when she uses the Withings Scale, it sometimes mixes up our readings.
This isn't an Apple accessory that's going to appeal to everyone, but if you're serious about reducing or maintaining your weight to improve your overall fitness, the Withings Connected Body Scale is certainly a great way to automatically integrate fitness information into a growing number of iOS and Web apps.