Calendaring for a small LAN

I'm looking at a small office with 4 PC's, and about to put in a LAN to
connect them. None of the PC's are run all the time, so the network would
either be set up as a peer LAN, ...OR, perhaps I could use one of the cheap
new Linux boxes as a server. Has anyone used something like the
much-discussed "Fry's special" as a server for a PC LAN? The PC users are
running a mixture of Win 98 and Win 2000.

One of the requirements is to install a calendaring system that would allow
each of the PC users to maintain his own calendar of client meetings, etc.,
and schedule meetings with other employees. This should include reminders of
coming events. Has anyone tried implementing something like this in
MySQL/Apache/PHP, so the PC users could browse it as an intranet
application?