TextExpander is a Mac and iOS utility from SmileSoftware.  Using automated expansion snippets it allows you to save keystrokes by carrying out things such as auto correction or insertion of boilerplate text.  It is also capable of sophisticated interactions through its field entry and scripting capabilities.  It can save you huge amounts of time and is probably the most sophisticated tools of its kind on any platform.

Make sure to Check out all of my TextExpander related posts as well as the Snippet Group pages where you can download the snippets and get documentation about what's in each snippet group.