get_stylesheet_directory_uri();
- returns the http:// path to either the child theme directory location or the main theme if no childtheme exists.

get_stylesheet_directory();
- returns the local directory equivalent location to the files either in the child theme if it exists or the main theme if no child theme

get_template_directory_uri();
- returns the http:// location of your main theme itself and never the child theme

get_template_directory();
- returns the local directory location of the main theme files

http://wordpress.org/support/topic/templatepath-vs-get_bloginfotemplate_directory