LDR Expression Pedal - Lovetone idea? Any good?

[Floyd Pepper]

This Ring Stinger comes with a "Light Jack"
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7418608273&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

This Lovetone Flanger one came "complete with the infamous 'light jack' which is a light sensitive controller meaning you can shape the sound by waving a hand or foot (or anything else) over the pedal"
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7415549104&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

From the RS pic it looks like it must be a stereo jack with a LDR in the end.

Has anyone tried or built one of these?  They must be interesting on stage with the light engineer working the expression for you.

[Unbeliever]

Fun to play with, but as you've noted unless you control both the source of illumination AND the means of blocking / adjusting that illumination it's very difficult to have a reliable and repeatable  effect. The UV-based systems that have both source and destination as part of the solution (I think Paul Perry / Frostwave makes such a device) are a better approach, IMHO.

[Processaurus]

LDRs are fun to play with those LED keychain flashlights.  You could put an LED on a cord (maybe have a parallel DC jack that it could plug into) for on sight illumination.

[Floyd Pepper]

LDRs are fun to play with those LED keychain flashlights

Now there's a great idea. 

[Floyd Pepper]

Just noticed you can buy the LoveTone light jacks for £5 from the old LoveTone distributer.

"Lovetone® light jacks -£5.00 +VAT; Certain Lovetone pedals use these plug in optical controllers."
http://www.dinosaural.com/prices.asp