Rob, a member over at 43Oh, wanted a quick way to add a digital display to his MPS430 Launchpad projects. So he devised a shield which he describes:
Here is a little LED Display Shield I have created for LaunchPad. It has 2 595′s, uses 3 wires to communicate with LP, and supports both, common anode and common anode displays. All LP’s pins are accessible on the shield, any pin can be used to drive the display. Four unused 595 outputs are also accessible. Transistors are MMBT3904 NPN for CC (R14 0ohm and R13 empty) or MMBT3906 PNP for CA (R13 0ohm and R14 empty.)
You can view more photos of this project and view the schematic by visiting the 43Oh forum page. (Forum registration required to view the schematic.) They also have the PCB and completed shield available for purchase.