Note: this post is from 2007, outbound links may be broken.
Rocksonics releases Telephone VST
This plug-in uses very steep, 6 pole high-pass and low-pass filters to create the telephone audio bandwidth of 350Hz – 3KHz. A granulizer reduces the resolution to 8 bits just like the phone company! Works with both mono and stereo signals.
For proper operation this plug-in must be used as an INSERT on channel, group or master outputs (the processor will produce no output when used as a SEND effect).