"Need to sync data between Google Calendar (Gcal) and your
desktop calendaring application? GCALDaemon, a nifty Java-based
utility, provides two-way synchronization between Gcal and
virtually any iCalendar-compatible application. Besides the ability
to sync calendaring data, GCALDaemon can act as a Gmail notifier,
and can pull your Gmail contacts via LDAP.
"To install GCALDaemon on Linux, download the Linux-compatible
zip archive, unpack it, and move the resulting GCALDaemon folder to
the /bin directory. GCALDaemon must be in the bin directory or it
simply won't work. And since GCALDaemon is written in Java, you
must have the Java Runtime Environment installed on your
machine..."