Here is a robotic arm based on an open source platform that helps you get started with Arduino and robotics. Th RobotGeek Snapper Arduino Robotic Arm has a modular design, so you can add parts, sensors, and additional components. It has a control panel that lets you control your robot right out of the box.
The Snapper Arm can be easily upgraded for your more advanced projects. It has high-torque servos that allow it to pick up 50 gram objects. The Gripper has adjustable angle finger tips. The Snapper Arm is controlled using a Geekduino board. More information is available here.