I can give you one coupon code under one of most knows hosting co maxim 3 domains name absolute free for register ( including dot com ) .
We're running a contest at our forums and offering "the owner of the Top Traffic Generating Thread -a Basic Dedicated Server free for Six Months, with a free domain for life". If you're interested to participate, check for more details at my signature links.
Actually here is the eBook for $4.99 that describes how to get virtually unlimited number of .com/net/org domains (it just takes time 5-7 domains/hour). Full DNS support.
Register.com gives a free domain (.com, .net...) for the first year. Requires a credit card. Transfer to a cheaper registrar before 11 1/2 months otherwise it auto-renews at $35. http://www.register.com/promo/acquisitions_8772090537.rcmx
No such thing as a free lunch dude, although there are registrars which are selling domains for as cheap as $1.99 (first year only, then they charge you for a very expensive price on renewal).
I can help anyone with a domain investment if the person has a potential website plan, I might need some help in return like a link back or something, we can sort it out.