There are many ways to do this, but let's start with some Lynxmotion pieces that are readily available at most online robotics outlets, including eBay and Robotshop. You'll want some servo brackets and other robotics hardware.
The item on the right is a standard servo bracket, and the item on the left is an extended body bracket. You'll need seven servo brackets and one main body bracket. Here are two additional pieces you'll need:
The one on the left is a C servo bracket, and the item on the right is an L connector bracket. You'll need three C servo brackets, and two L connector brackets. You'll also need six standard size servos for this project.
Note
You can purchase each of these separately, but if you'd like you can buy the 17DOF Biped Robotic Educational Robot Humanoid Robot Kit Servo Bracket on eBay, which will come with all the servo bracket parts you'll need to build your Wall-E.
You'll also need three lengths of aluminum tubing, 3 inches in length, and six...