Need to watch log files in real time? Found the following tools quite useful for this.

Intall the following

apt-get install xwatch logtop whowatch

xwatch – great tool for xwindows, do: ssh -X mrfoo@myserver xwatch /var/log/auth.log  or whatever log you want to follow

or use logtop

 tail -f auth.log | logtop

Live update of who is logged in or logging in:
whowatch