I'm reading "The Confident Hope of a Miracle", which is about the Spanish Armada's failed attack on England in 1588. There was a passage describing the Armada's leave-taking of Spain which reminded me of a lot of the software failures you read about:

As the vast Armada set sail on the afternoon tide, the Pope's special emissary to Lisbon sent a report to the Vatican of a conversation he had held with one of the highest officer's in the Spanish fleet.

"If you meet the English Armada in the Channel do you expect to win the battle?"

"Of Course"

"How can you be sure?"

"It's very simple. It is well known that we fight in God's cause, so when we meet the English, God will surely arrange matters so that we can grapple and board them, either by sending some strange freak of weather, or, more likely, just by depriving the English of their wits. If we can come to close quarters, Spanish valour and Spanish steel (and the great masses of soldiers we shall have on board) will make our victory certain. But unless God helps us by a miracle, the English, who have faster and handier ships than ours and many more long-range guns, and who know their advantage just as well as we do, will never close with us at all but stand aloof and knock us to pieces with their culverins without our being able to do them any serious hurt. So, we are sailing against England in the confident hope of a miracle"

If your business or project plan resembles that last paragraph, then it's probably time to pack it in. I'd wager that a lot of "web 2.0" business plans are setting sail in the confident hope of a miracle.