For anyone interested in using Github to host their Jekyll-based site, you don't even have to install Ruby and Jekyll locally -- just "git push" and Github runs Jekyll server-side and hosts the generated HTML on Github. You can then set up CNAME records so that traffic to yourblog.com is served by github.com. All for the low low price of free:

https://github.com/blog/272-github-pages

http://pages.github.com/