Mine

#!/usr/bin/python

import os, sys, time, signal

XORG_DELAY = 8

if len(sys.argv) == 1 or (len(sys.argv)==2 and sys.argv[1].startswith('-x:')):
        print >>sys.stderr, "Usage: %s [-x:id] app [args]" % sys.argv[0]
        sys.exit(2)

if sys.argv[1].startswith('-x:'):
        xid = int(sys.argv[1].split(':')[1])
        argv = sys.argv[2:]
else:
        xid = 1
        argv = sys.argv[1:]

pid = os.fork()
if pid == 0:
        # Xorg child
        print " * Staring X11 on :%d" % xid
        sys.stdin.close()
        sys.stdout.close()
        sys.stderr.close()
        os.execvp('X', ['/usr/bin/X', ':%d' % xid])
else:
        print " * Waiting for X11 to finish starting (%d seconds)" % XORG_DELAY
        time.sleep(XORG_DELAY)
        cmd = 'env DISPLAY=":' + str(xid) + '" ' + ' '.join(argv)
        print " * Starting %s" % cmd