https://www.godaddy.com

Here's a bunch of handy coupon codes you can use at American internet domain registrar and web hosting company GoDaddy.com. Coupons are entered at the checkout. All prices are US dollars.

OYH3 - $6.95 .com domains (this should also work for renewals)
TPS7 - 20% off on any order of $50 or more
BTPS20 - 25% off on any order of $100 or more
hash2 - $5 off on any order of $30 or more