I was surprised to see that my installs of Ubuntu 9.10 and Ubuntu 10.04 server didn’t have ntpd in them. This meant that nothing was correcting my drifting time. One machine was off by five minutes.
So I installed OpenBSD’s ntpd: sudo aptitude install openntpd
And then started it: sudo service openntpd start
The /etc/openntpd/ntpd.conf shows that I’m polling from the Debian NTP server pool. I guess that’s good enough. When I need an NTP server and can’t remember, I use time-a.timefreq.bldrdoc.gov.