You can clone with
HTTPS or Subversion.
Consider adding the ability to exclude files based on a regexp.
The above in _config.yml will make sure less (http://lesscss.org) files aren't copied over to the generated site. I think this functionality would be useful for others using Jekyll.
This is a nice idea, but I don't want to support putting random regexps inside of the config. I'd accept a PR that used just a normal glob syntax that would work in any shell, and Dir.glob. Going to close this for now.