While breadboard loggers are quick, the connections tend to be a bit too fragile for serious testing. So I've come up with a configuration based on a screw-terminal expansion board that breaks out all the pins nicely:

Arduino Data Logger: 2017 Build Update

As a bonus, I've also described modifications that bring this 4-part logger below 0.02 mA sleep current. Current assembly time for the basic unit is under one hour.