The linux program that is capable of reading the SPD bits from memory chips is called ‘lshw.’

Description: information about hardware configuration
A small tool to provide detailed information on the hardware configuration of the machine. It can report exact memory configuration, firmware version, mainboard configuration, CPU version and speed, cache configuration, bus speed, etc. on DMI-capable x86 systems, on some PowerPC machines (PowerMac G4 is known to work) and AMD64.

Information can be output in plain text, HTML or XML.

Hopefully someone else will find this information useful, but I’m writing it here so that I will always have a reliable place to look for it the next time I forget what the command is.