I'm going to create a new website and I wonder if I can get ranked on a position in Google faster when I build it on a domain that is about 6 months old now? (it is indexed and I have put on a simple site, but almost no backlinks yet) Or should I just get a new domain and the result will be the same? Does the domain age (= the time how long has the domain been registered) play any role in Google rankings? I'm not talking about backlinks or content, just purely the age of a domain.
As long as you didn't bothered to build backlinks on your 6 months old domain, I'm afraid Google will see it as any other new domain. Working on your website and increasing the number of backlinks you have will give you credibility, not just setting up a page and leaving it there somewhere. I'd say it really doesn't matter if you choose a new one or that 6 months old domain in this case.
I believe that Google age is important for Google. But that is only my opinion, I can not prove that.
Domain's age is important in terms of credibility and trust rank which implies that you constantly work on your website. Don't expect to register a domain, put it online, leave it for 20 years and then build 5 backlinks and get the top positions in SE's
Yeah, it's PR3, as I linked to it from my other PR3 site. However, I now removed the link, as I needed to link from this site to the other, so now it has almost no any backlinks.
I'd go with the old one as well, although 6 months don't really qualify a domain as aged in terms of trust rank, so the advantages compared to a totally new domain aren't huge, but even a slight advantage is an advantage...