Amazon $20 off $100 coupon works on Android accessories (among other things) :D
For peeps who are looking to pick up some accessories for their Nexus:
"Amazon.com customers get a $10 discount off your order on MasterCard Savings Days when you use your MasterCard® card to purchase $100 or more on products sold by Amazon.com. Customers who complete their qualifying purchase on Savings Days will receive an additional $10 discount to use towards a future purchase when you use your MasterCard® card to purchase another $50 worth of products sold by Amazon.com. "
Use the code generated at: MasterCard® Savings Days Promotion
Hope that helps :)