Microsoft Office Live Basics offers free top-level domains for new users however you must use their hosting which is quite limited in features.
Many hosting companies offer free domains with annual subscription plans. Ex. ixwebhosting. I never used this option though because I don't believe in free meals.
I think you can still get free domains at dot.tk http://www.dot.tk And free subdomains at co.cc http://www.co.cc/ Or you can register a .info domain at godaddy at just .99 cents for the first year.
Did you ever try domainlagoon.com Pretty simple you do surveys you get points and you get a free domain. I have gotten 10 from them so far.
if .com/.net/.org/.asia and etc, i dont think there has free unless u win a content at a blog/forum or somewhere else. if u want sub-domain like dot.tk or co.cc, then it free at all.
What kind of domain do you want and what kind of site do you want to make? I have some short, generic domains I'm not using and I *might* consider letting you use one as long as it's not a porn site or warez or something that will caue me problems. I'd want to put an ad and lnks to my other sites. I also have a linux server but access would have to be very limited.
They're only do redirection for free. You have to pay them for control of the domain. I usually suggest using http://uni.cc It's only a subdomain but they allow you to control it and do the DNS for it as long as you follow their rules.
these guys gave a lot of good options but the thing is. its obviously not completley free. u will either have to do something for them, or u will just be limited.
I think you should consider some reliable company instead of looking for free domain. After all these days registeration is not costing much.
You can get a free subdomain at ZooLoo.com - (example.zooloo.com) It's also free to host your site there as well as use the site building tools.