LeadsLeap & Wikipedia

Leadsleap
http://www.leadsleap.com?referid=theplan
Even though that's my affiliate id.. it's still a free site :)
You don't need to buy into their pro version, the main reason you'd want to sign up is because they send great free marketing tips, and have heaps of free bonuses to download where half these ideas came from.. :)

Wikipedia
http://www.wikipedia.com
If Wikipedia.com links to your site, your pagerank goes up.