Tactigon
The Tactigon is a literal handheld device. It wraps around your hand to detect your movements and translate them as commands to a PC or a robot. It is packed with ST sensors since it uses the WESU reference design. Its Arduino board makes it particularly attractive to developers. First of all, they get to benefit from a huge community. Second of all, mature tools, such as the Arduino SDK, will facilitate programming operations. It is thus a great way to introduce enthusiasts to alternative interfaces.