--- a/carton.py	Fri Jul 08 15:23:04 2011 -0700
+++ b/carton.py	Fri Jul 08 15:35:53 2011 -0700
@@ -26,6 +26,8 @@
 virtualenv_url = 'http://pypi.python.org/packages/source/v/virtualenv/virtualenv-1.6.1.tar.gz'
 template = """#!/usr/bin/env python
 
+"create a virtualenv at %(ENV)s"
+
 import os
 import shutil
 import subprocess
@@ -48,6 +50,14 @@
 VIRTUAL_ENV='''%(VIRTUAL_ENV)s'''.decode('base64').decode('zlib')
 PACKAGE_SOURCES=%(PACKAGE_SOURCES)s
 
+# parse options
+usage = os.path.basename(sys.argv[0]) + ' [options]'
+parser = OptionParser(usage=usage, description=__doc__)
+parser.add_option('--env', dest='env', help="environment name [DEFAULT: " + ENV + "]")
+options, args = parser.parse_args()
+if options.env:
+    ENV = options.env
+
 # unpack virtualenv
 tempdir = tempfile.mkdtemp()
 buffer = StringIO()