Updated the useage instructions to mention that you need to use the python interpreter to run it
diff --git a/oacurl.py b/oacurl.py
index ffb3a4d..740baf2 100644
--- a/oacurl.py
+++ b/oacurl.py
@@ -127,8 +127,8 @@
 
 
 def main():
-  usage = '''Usage: %prog [options] fetch <url>
-  Example: %prog -v fetch "https://www.googleapis.com/buzz/v1/people/@me/@self?alt=json&pp=1"
+  usage = '''Usage: python %prog [options] fetch <url>
+  Example: python %prog -v fetch "https://www.googleapis.com/buzz/v1/people/@me/@self?alt=json&pp=1"
   '''
   parser = optparse.OptionParser(usage=usage)
   parser.set_defaults(verbose=False)