This is pretty simple. Instead of performing a WHOIS inquiry and sending out spam emails to buy or trade links, I try to make friends with other webmasters... social media anyone?
Hoon yes social media is most useful way now-a-days, hope you are talking about del.icio.us, twitter, digg etc. Also facebook, they are all good way to at least introduce your content.
The place you can get other webmasters' contacts is by hanging out on webmaster forums. That way you can ask for link exchange in the appropriate place. But thats not the only place to get links (reciprocal links). Yuo can buy links, join link wheels and blog farms and blog networks also to get backlinks.
I think the directest way is to purchase links.To exchange links with others is good,but you can't make sure others will be absolutely willing to cooperate with you.