Decided to start stashing my Gradle odds and ends somewhere for future reference...

build.gradle

// Create a tar file from a filtered tree of files
// e.g. a tree of Python Source files

project.ext {
  pythonFiles = fileTree('src').include('**/*.py')
}

task tarPythonFiles (type: Tar) {
  from pythonFiles       // Source is our fileTree
  includeEmptyDirs false // Otherwise we get ALL the dirs in the fileTree
  baseName project.name  // Name is taken from the project directory
}