Similar to crop dusting, vapor trailing involves farting while walking, but in this case instead of passing someone standing still, the person is walking behind you. Based on the vapor trails that high flying jets make.
I just vapor trailed the poor sap behind me like I was an Airbus A330.
The electronic equivalent of a "paper trail". In the old days, guys like Enron and MCI had to worry about leaving hard-copy memos and such laying around that could eventually be used against them. Now it's e-mails, text files, server databases and the like.
Enron's IT guys are trying furiously to erase the vapor trail.