The BitBar app lets you put the output from any script or program right in your Mac OS X menu bar. And it’s completely free. An impressive number of plugins have already been contributed by a wide range of developers just like you, and this site makes it easy to find them.
I hope you find something useful in our repository (you can use the links to the left or the search above to have a look around). If there’s something missing – please consider contributing a plugin of your own.