The mgetty package contains an intelligent getty for allowing logins over a serial line (such as through a modem) and receiving incoming faxes. The companion program sendfax is used for sending faxes from the commandline or from other applications. The third main component is vgetty/vm which can be used with a voice-capable modem to implement an answering machine, a voice menu system, and similar things.
Playlist Warlock is a text-based frontend for mpg123 written in Perl. It is intended to provide users with the playlist browsing and song selection of a GUI MP3 player from any terminal. It provides a combination of Winamp/XMMS, vi/less, and Unix prompt-style commands for creating, editing, sorting, and navigating MP3 playlists. Using mpg123 as a backend, PLWarlock allows the user to easily browse playlists and play MP3s. It supports contiguous and random play, simple jump-to-song syntax, sorting by filename/path+filename, and all the other commands you've come to expect from a good MP3 player.