(I posted this earlier, but under the wrong category)
Just an FYI that in Rev 2 of the Arduino Protoshield kit the general I/O button is no longer wired like the schematic -
i.e. Gnd->S2->JC1->R4->Vcc.
Instead it is now wired: Gnd->S2->R4->JC1.
Was curious if this was an intentional change.
Also note that the analog pins are labeled backwards from that of the Arduino on this revision.