There is a Nagios plugin available through which services monitored by Monit can be monitored - http://code.google.com/p/nagios-monit-plugin/
But there are a few limitations to this script like -
These issues are catered by this updated version of my check_monit.py script submitted as a patch at http://nagios-monit-plugin.googlecode.com/issues/attachment?aid=20000000&name=check_monit.py.patch&token=32qXj5orfcsWNcrbIZ4gvT5WoPA%3A1328588504677
But there are a few limitations to this script like -
(1) Added granular information about services like Load, Memory and HTTPD information monitored by monit. (2) Added compatibility with Monit version 4.9 and version 5.2.5 to show the details mentioned in point (1) (3) Added performance data for the results, so that trend graphs can be plotted
These issues are catered by this updated version of my check_monit.py script submitted as a patch at http://nagios-monit-plugin.googlecode.com/issues/attachment?aid=20000000&name=check_monit.py.patch&token=32qXj5orfcsWNcrbIZ4gvT5WoPA%3A1328588504677