The CD/ROM in my computer busted, so I decided to try to remotely mount the CD from another computer on mine. I know the MacBook Air can do this, so I reasoned that any Mac could. It turns out it is possible, but the solution is far from obvious -- after much searching, I found the solution here.

Here's a quick synopsis. Go to System Preferences » Sharing, and enable 'DVD or CD Sharing.' (I think you need to do this on both machines -- the one with the drive and the one without the CD/ROM drive). Then, on the computer that does not have the CD drive on it, go to a Terminal window and enter:

$ defaults write com.apple.NetworkBrowser EnableODiskBrowsing -bool true
$ defaults write com.apple.NetworkBrowser ODSSupported -bool true

Reboot this machine, and when the reboot is finished, you'll see the remote CD/DVD under Devices in the Finder's sidebar. Thereafter, you can remotely mount a CD/DVD from another machine.

[robg adds: The linked hint gives credit for the Terminal commands to this MacRumors forum post. I haven't tested this one yet.]