In this instructable, I go though how to create a mount for a Nexus 7 Android tablet. It's light, cheap, and does what it is designed to do really well. Basically, BEST. ANDROID. ACCESSORY. EVER.
This can also be adapted to fit other controllers and other Android devices.
I made this at TechShop. The tools there really helped make this doable.
Step 1: Materials
Hopefully you already have at least these things laying around your house.
Nexus 7 Tablet - $200
PS3 / Xbox controller - $50
For the Mount
1/8" dia x 48" Mild Steel Rod -$3 (OR 1/8" dia x 48" Copper Rod)
48" of 1/8" MDPC Expandable Tubing - Comes in packs of 20' rolls for $7
This is the stuff that people use to manage cables inside of computers. But you want to have a flexible tube that won't scratch your device.
1/8" Heat Shrink Tubing - $2
For some grippy stuff and to clean up the ends.
A big vice