If you want to register new domains in May 2009 from Namecheap, here is the coupon code you should use: FLORESCENCE. With this code, you will be able to register domains for as little as $8.81 (instead of the regular 9.69)!
The domain renewal coupons of Namecheap are available only to their high-volume customers.If you have more than 50 domains registered with Namecheap, you can request a domain renewal coupon code by contacting their support. It would not only save you money on domain renewals but also Whoisguard renewals, just in case you use it!