If you came to my website recently, you should have noticed that my website now have SSL enabled, but the certificate may not be trusted.
Settig up SSL is trivial, but setting up SSL with a trusted certificate is difficult and expensive.
I dont have all those spare money. That is why I used a free (but trusted by free software community) CA, CACert (http://www.cacert.org/) You can visit their page for their root certificate and trust that. That will automatically make your browser trust my website.