Rocksonics has announced the release of Megaphone - an Amplified Bullhorn Emulator. It sounds just like hand-held bullhorns and horn PA speakers. It combines the grit of a carbon microphone, distortion of a cheap amplifier and the mid-range honk of a hard-shelled horn speaker. Megaphone is a simple, on/off, non-gui plug-in that works in stereo and mono as an insert effect.
Megaphone costs $5 and is available as a VST effect plug-in for Windows.