After coming across a set of scales used with the stamps.com service, Oleg from Circuits@Home spent some time and has documented how to interface them with an Arduino via a USB host shield. As the scales don't have a display - the data instead is sent to a host PC for use with an online stamp purchasing service - they're quite useless for any other purpose. However as the scales have a USB interface, Oleg has published a simple sketch which interprets the weight data from the scales' USB output and displays it on a typical Arduino-compatible LCD module.
A great example of using an Arduino to make something useful again. After a quick look on ebay, there seems to be plenty of these scales available, so if you're up for some scales hacking, visit Oleg's interesting website. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're looking for an Arduino-compatible board with inbuilt USB host shield, look no further as we have the Freetronics USBDroid board:
Apart from being a fully Arduino Uno-compatible, it has onboard microSD socket and the full USB socket and host-mode controller. As well as the Bluetooth application described above, this is the ideal platform for developing peripherals or projects based around Android devices with ADK (Android Developer Kit) functionality, but without requiring a USB host controller shield stacked onto an Arduino. For more information and to order, visit the product page here.