http://username.github.com/pages.html
http://username.github.com/sitemap.txt
http://username.github.com/categories.html
http://username.github.com/archive.html
http://username.github.com/index.html
http://username.github.com/tags.html
http://username.github.com/atom.xml

http://username.github.com/lessons/2011/12/29/jekyll-introduction