While not particularly exciting, this collection of functions have proved invaluable to me during development. Their focus is on shorthanded output of variables, and exiting the current flow.
I thought about showing examples here, but they all pretty much speak for themselves. Just call the function with a parameter, and see what happens :)
For more information, check out the blog post I wrote, overviewing it:
http://web.onassar.com/blog/2012/06/08/github-project-php-debugging-development-functions/