Before modifying critical system files, make a backup copy
using the date as an extension:
$ cp /etc/hosts /etc/hosts.971006
If you keep a number of these they provide a potentially
valuable archive as well as a means of finding out any
changes that have been made and when.
NOTE: All tips provided are USE AT YOUR OWN RISK. Tips are submitted
by various unix admins around the globe. UGU suggest you read and
test each tip in a non-volitile environment before placing into
production.