Since this might be of interest to you too:
Introducing, a dirt cheap but very handy digital clapperboard.
It behaves like a hardware digital clapperboard, but can do a few tricks more. Most important extra feature is that you can use it for playback of songs with matching TC.
Very handy for shooting videoclips.
Now i do realise that on a video clip set with playback via a ghettoblaster it is uncommon to have a soundguy, but since you probably know more about timecode than the average shooter i thought it could be good to know.
For regular work, if you have a BWF recorder you probably know the value of visual reference in case of trouble.