Now that the HESA is up-and-running, I finally made a backup of the SD card. Basically, you use the same Win32DiskImager software that you used to install the Raspberry Pi distribution on the SD card. Lifehacker has some good instructions for backing up the SD card. I'm not going to repeat the instructions here.
Not only did I make a backup of the SD card to the C: drive of my computer, I installed the backup image to a new SD card and installed the copy in the Raspberry Pi. It worked perfectly. The RPi is running it on as you read this. Awesome!
One interesting thing is that the original SD card was 4gb. The copy I made went on an 8gb SD card from a different manufacturer. I was skeptical that it would work but that was the only extra SD card I had.
By the way, I've already dropped two screws into my sump crock. I think I need a better way to attach the acrylic to the front of the enclosure.