SD memory cards, especially the ones under 1GB are cheap, relatively easy to interface and provide vast amounts of memory for imbedded control.
This device lets you 'talk' to sd cards through your serial port. Communication is in ASCII so you just need a terminal program to access it. (Note: the photos shown are of the rev-1 device with various changes, documentation is for the rev-2).
SD sockets are available from SparkFun Electronics. The socket needs to be surface mounted so it was placed on the foil side of the single sided board (mouseover image above to see). The connections are close to 0.1 inch centers, so the layout was not difficult.
The PIC16F819 was chosen for its