I had the same problem, before Celery existed. The hardest problem was, in my view, the fact that Python's built in HTTP daemon does not support authentication (HTTP digest), so if you want your web server to communicate with a daemon on another machine, it's not quite as simple as using HTTPDaemon and a pool of subprocesses.

My HTTP/digest enabled HTTP daemon is here.

To be used like so:

from Exscript.servers import HTTPd, RequestHandler
class MyHandler(RequestHandler):
    def handle_GET(self):
        if self.path == 'start':
            # Start subprocess here.
            self.send_response(200)
            self.end_headers()
            self.wfile.write('Script started!')
        elif self.path == 'status':
            # Status request goes here.
            self.send_response(200)
            self.end_headers()
            self.wfile.write('50%')
        else:
            self.send_response(404)
            self.end_headers()
server = HTTPd(('', 8080), MyHandler)
server.add_account('testuser', 'testpassword')
print 'started httpserver...'
server.serve_forever()