altho instead of installing ntp oneself, this seems worth a try
http://forum.xda-developers.com/showthread.php?t=688177
(requires root, natch)
installed from market and seems to work just fine. does what it says on the tin.
looks like it is just a standard ntpdate/ntpclient rather than a proper ntpd, so it will jerk the clock around instead of gracefully drifting it, but still.
also in the settings there is some sort of "rootless" mode but I was not able to test it.
good enough.