I felt like building an FPGA slice, so I did.

Based somewhat upon Nick's Blog entry here.

Sorry for the bad photo, my phone has issues.  

Essentially the bottom three ICs are 74hc595 (CMOS logic levels) for allowing an arduino to program the slice.  The three ICs up top are two 8:1 MUXs and two D flip flops. The oscillator up top is connected to the D flip flops, so they always have updated values.

I used CMOS chips because I did not have enough TTL MUXs, even though I have plenty of every other TTL IC...

I may consider making many FPGA slices and connecting them together one day, with printed PCBs and such.  Those would have DIP switches instead of 74595s because DIP switches are more fun to program.