I've been wanting to do this for a couple years, and this was the summer to do it, apparently. I feel like I'm far enough now that I have some decent progress to show, and especially to see if any of you guys can spot anything I'm doing horribly wrong. I think I've got this set up so that if you click a picture, you get the big version of it.
CABINET CONSTRUCTION
Transporting the wood home from Lowe's:

Cutting out the sides:

Dadoed wood for the base:

The sides and front go up:

Test-fitting and securing the monitor:

That monitor is a beast. It's a 32" Mitsubishi video production monitor thing, I found it on Craigslist for $20, and it probably weighs close to 200 pounds.
CONTROL PANEL
Test assembling the control panel:

THE COMPUTER
Under construction:

The computer is a P4 2.4 GHz, 1 GB RAM, 40 GB HDD.
Before somebody mentions how dangerous it is to run a power supply without its cover on,

I know. I got careless late at night while getting the PC ready, reached around the back without thinking about it to grab a cable, saw a flash of light and yelled louder than I have in a long time, and walked downstairs to see what my surgeon dad thought I should do. That black isn't dirt, it's burned skin. At least I'll have a cool scar. You'd think that a Computer Engineering student would have a little bit more reverence for electricity, but I definitely do now.
As far as artwork goes (Galaga is one of my all-time favorite games):
CPO:

Marquee:

Side art to come after I graduate from Clemson in December and have a little more time to play with it.
I've got all my buttons and joysticks ordered and sitting in a box in my room, and I'm working on hacking a spare mouse I had to interface with a spinner knob and with a trackball I had sitting around from a Golden Tee TV Plug and Play game. I can't really start building the CP until I get the trackball functional. If I can't get it to work tonight, I'm just going to break down and order the X-Arcade trackball.
Also, a guy a couple streets over was throwing away an old Prospector pinball machine. He was trying to move it and it fell off the back of his truck. I wanted to salvage it, but it was way, way gone. So, I took the coin door

It'll look like this after I clean it up and Brasso the scratches out (not my picture):

So, what do you guys think? Tonight's project is mounting my speakers, getting the trackball working, and cleaning up the coin door.