Smart watches are the new smart things to wear now, and most companies are planning at least one product in this market. You may be heard of Samsung Galaxy Gear, or Pebble. If you can’t afford one or you are interested in creating one yourself here is a cool article which will tell you how to create an open source do it yourself smart watch.
Things you need to have
Arduino micro-controller
Bluetooth module
Smart watch Display
Battery
Wires
Soldering iron
Switch
10K ohm resistance
Watch a working demo here
RetroWatch Specifications:
Processor : ATmega328 – 3.3v(8MHz)
32KB Flash (2KB is shared for Bootloader)
2KB RAM
1KB EEPROM
Size : Width x Height x Depth = 34mm x 32mm x 12mm (Not packaged)
Battery : LiPo 140mAh (idle time 6-7hrs, 1-2hrs for recharging)
Connecting with Android app
Supports notification, system info, RSS feed
Message filtering
Open source
Here is the step by step instruction on Instructables