The schematic is designed using TinyCAD
http://sourceforge.net/projects/tinycad/

The stripboard was laid out using VeeCAD
http://veecad.com/

It is loosly based on an Elektor circuit
http://www.elektor.com/magazines/2002/march/iec1107-electricity-meter-interface.55617.lynkx

The photodiode is an OSRAM BP104, the IR LED a generic IR LED from Jaycar
(ZD1947) with a spectral peak of 940nm. The opamp is an LM348 clone (ZL3348 from Jaycar).

The 6 pin interface is a TinyOS FTDI breakout
http://www.tinyosshop.com/index.php?route=product/product&product_id=186

Mine is running at 5V but it works at 3.3V.

I needed to use the FTDI EEPROM tool to invert the TX & RX sense using FT_Prog from
http://www.ftdichip.com/Support/Utilities.htm

The need to invert could be rectified by modifying the circuit, but modifying the
EEPROM was a lot easier than changing the circuit.