Yahoo Domains - $1.99
Here is another $1.99 domain promotion, this time from Yahoo Small Business.
Discount: $1.99 any domain registration
Limitations: new customers, one domain per customer account
Although, it is not difficult to set up additional accounts for this purpose.
Offer expiration date: June 30, 2007
Promo code: You must go through this link to get the discount. Otherwise, all domains will show up at $9.95/year