I wrote a little mod_rdate if anyone is interested, http://www.sysdesign.ca/archive/apache/module-experiment/mod_rdate.c
rdate allows a host to synchronize its time to a server, with approximately 1-second accuracy. It is far inferior to NTP but so much simpler and still my preferred method for dealing with drifting clocks. It gets the job done. In /etc/services, port 37 is the "time" service. Upon connecting, the client simply reads back a 32-bit value representing seconds since 1900. My mod_rdate.c is NOT well tested, and may not be very portable. But hey, there you go, arbitrary protocol :)