The design was roughly based on this design.  We started with two 8' x 4' sheets of particleboard and sketched out all of the cuts we wanted to make.  All of the square cuts were made on a table saw, and the curves were cut with a jig saw.  For the curves, both sides were stacked to ensure symmetry.

We built the square base with 2x4s and topped it with 1/2" MDF.  We added casters (wheels) to make it easier to move around and attached the rest of the frame with countersunk 2" deck screws.

Next, we filled the countersunk screw holes and sanded, primed, and painted it all surfaces.  We applied the black oil-based enamel paint with small rollers.

For the speakers, we cut two 4" diameter holes in the top section and covered them with speaker grills.

We used a 1 1/8" spade bit to drill holes for the buttons and joysticks on the control panel.  The buttons and joysticks have microswitches, which we wired to an Ipac.  The Ipac connects to a PC via USB and behaves like a standard USB keyboard.  Note: If you order an Ipac, be sure to pay for the tracked shipping.  We didn't at first, and ours never arrived.

We ran an angled 2x4 down both sides in the front for the acrylic (plexiglass) to rest on.  We measured the monitor and spray painted the plexi, leaving only monitor viewable.  We mounted the monitor on a piece of particleboard using its VESA mount holes and screwed it to the back of the 2x4s.

Finally, we attached two remaining pieces of particleboard to the back using simple hinges, with open space at the bottom for ventilation.

 The sides after the curves were cut.

 Geoff adding casters to the base.

 The completed frame, before wood putty covered the screws or the speaker holes were cut out.

 After wood puttying the screw holes, test-fitting the control panel.

 The completed frame from the back, with primer applied.

 The painted frame.

 The control panel with holes cut.

The control panel with buttons, joysticks, and a plexiglass cover.

 The underside of the control panel, with one player's microswitches wired to the Ipac.

 The monitor mount in the back.

 The final, assembled machine, taken when it was initially installed in Chez Bob.