I ran an ANT task to undeploy an ATG Module, but I had my build property module location set incorrectly. As a result, I inadvertently deleted my entire ATG 7.1 installation.
I opened the containing directly in the Finder, where my ATG 7.1 USED to be, and hit TimeMachine. My laptop connected to my Time Machine over wireless, and let me browse through the last month or so of folder states for that directory. I went to the previous backup (about half an hour ago), and clicked Restore. Like magic, my entire missing ATG installation reappeared.
Pretty sweet stuff. Thanks Apple.