Tool for activating and deactivating groups of lines in /etc/hosts. This probably could have been a few lines of sed but whatever. :)
To use it, put <foo> at the ends of some lines in /etc/hosts.
hostgroup --off foo
comments those lines out, and
hostgroup --on foo
uncomments them.
hostgroup --groups
shows a list of all the groups in /etc/hosts.
hostgroup --list FOO
shows all the lines in group FOO.
The --path PATH option can be added with any other commands to change the path to the host file (default is /etc/hosts). The --dry-run (PATH) option writes the updated file to PATH (or to stdout if PATH is not provided) rather than overwriting the hosts file.