get path to groovy source file at runtime

Given the following directory structure:

/home/some/random/foler/myScript.grooy

... how can I programmatically obtain the path to myScript.grooy parent directory right in the script itself?

Ultimately I'm trying to read in several files from the same directory the script is in.

EDIT: trying to run it on Windows 7, Groovy 2.0.1, groovy console