Spectator Mod

Spectate everyone on the server.
Unfortunately it does not display names, but you can call the spec function with a string argument to spectate someone specific.

Usage

Type spec into console. Use A/D (LEFT/RIGHT) to switch between players.
Type spec pla to spec a player whose name has pla in his name (would for example spectate on "player" now).

Features still needed

1. Display the name of spectate target (can't send chat messages to player while spectating with Chat_ServerPrivateMessage or use OBS_MODE_IN_EYE on to display name card, because OBS_MODE_IN_EYE/THIRD_PERSON seem to only work on same team).

ConVars for chat announcements

You can use following ConVars to edit the config on the run or add them to your autoexec_ns_server.cfg to set them.

spectator_chatinfo
Accepted values: true, false
Default: false

spectator_chatinfo_interval
Accepted values: any integer
Default: 300 (5 minutes)

spectator_chatinfo_message
Accepted values: any string
Default: "To spectate type spec in the console. Press A/D (LEFT/RIGHT) to change player."