The Horntones car-horn enhancer

What It Is: So you're sitting in traffic and the car behind you is feeling a little antsy. The driver leans on the horn and you hear not a harsh toot but a lion's growl.

Fans of cellphone ringtones have a new outlet for self-expression: Drivers now can update their car horns with downloadable tones, including libraries of songs.

Some horns can even be equipped with recording capabilities.

How to Get It: With Horntones' FX-550 system, an MP3-enabled horn-enhancer, songs can be downloaded from the Horntones Web site in sets of nine tones and grouped into themes ("tailgate" or "car pool") that you can call up to suit your mood.

The files are then uploaded via a USB connection. Coga's musical car horn, the COGApa, comes preloaded with 80 sounds and allows drivers to record new sounds with a built-in digital recorder.

It also doubles as a public-address system when you really want to get someone's attention. Wolo's Jukebox Musical Horn includes 34 preprogrammed songs, plus a remote that works like a keyboard and allows users to add one song.

Full article continued at The Wall Street Journal: Reinventing the Wheel.