I made it at Techshop with their 65 watt laser cutters and my trusty Dremel. I've also been charting my progress on the rack (and the bike it's going to go on) at CurmudgeonBicycles.com.
A couple of sheets of plywood small enough for the laser cutter but big enough for your deck.
Lots of clamps.
400 grit sand paper.
00 grit artificial steel wool.
Step 1: LASERS
Plus, you know... LASERS.
The laser cutter basically functions like a printer. The darker a color is, the more power the laser pumps out. You set it up for your materials, do some trial and error, and then burn the hell out of whatever you're etching. Specific line widths trigger a vector cut (I usually just use .0001), which is usually set to cut all of the way through.
I found that the techshop recommended power settings needed to be tweaked a bit. The plywood was a bit harder to punch through than normal wood... so I set up a bunch of test cuts at the bottom. Find something that makes it through the first ply for the images, you'll be glad to have the extra depth later when you're finishing and sanding.