This Arduino R3-compatible shield makes it easy to add a 'hard disk' with gigabytes of storage to almost any Arduino, saving data to files on any FAT16 or FAT32 formatted SD card. The shield includes a real-time clock that can be used to timestampp collected data, and two free software programs demonstrate how this data can be plotted using common spreadsheet or analysis programs. Adding headers can be done easily in less than 15 minutes.