ttywatch -- Log output of arbitrarily many devices
http://www.danlj.org/mkj/ttywatch/
ttywatch was originally designed to log serial console output from lots
of Linux machines on a single monitor machine. It handles log rotation
correctly and can be configured both in a configuration file and on the
command line -- and you can mix-and-match at your convenience. It can be
set up to allow users to interact via the network with any of the ports
being logged. It can also log output in arbitrary ways via modules,
which can be built with the ttywatch-devel package.