[sandermarijn]

At least a few years ago, there was a guy in the Netherlands selling adapters--basically he was carving the shells of old batteries, soldering in a resistor, and leaving space for the new battery inside. I bought a couple for my Nikon. If I remember when I get home, I'll see if I can find his info.

That's Frans de Gruijter. His tutorial contains a *lot* of useful technical information, almost a must read: http://www.buhla.de/Foto/batt-adapt-US.pdf

You can email him at battery.adapter@orange.nl to check if he's still in business- it's been a long time since I ordered from him.