I have created the Tarpipe.com Api PHP implementation.
The source can be found out on Google Code, Tarpipe PHP.
A simple example of use could be:
$key = "YOUR_WORKFLOW_KEY";
$client = new Tarpipe_PHP($key);
$title = "Playing with tarpipe.com PHP_API";
$image = "directory/someimage.jpg";
$body = "Some body on you message";
It’s my contribution for the project, that even if it is on a “developer preview” version is already making me smile, with the potential of the project.