I also patch my clients not to accept time corrections from the bitcoin network and think that the clock skew acceptance built in to the bitcoin network is insane. Or at least silly and out dated.
It would be great if you contribute it back to core so that others can enable it as an option.
With regards to the suggestions of integrating NTP into the bitcoin client, I think it is a bad idea. The bitcoin client is simply not an appropriate place to put timekeeping software.
If I were emperor, I would make the client turn red if it thinks the local clock is off by more than 5 seconds from what the peers report, and refuse to run if off by more than 30 seconds.
gtk-gnutella has an amazing statics view in the user interface. It tracks 100's of variables. If similar data was just made available from the command line, I would write some munin plugins to graph the data.