Also your telegraph analogy is something I've seen in several places and doesn't seem to mean anything. Plus I'm not really comparing Bitcoins to bank I'm more curious about the viability of a pump-and-dump system with a finite amount of units. If it's all based on speculation who is ever gonna spend the stuff?
The logical point I keep ending at is that you need a buyer. AS SOON as it starts to dip down, everyone will smell "crash" and then how do you sell them? The bubble bursts. From then on I think 1 of 2 things will happen.
1. The system will completely fail in marvelous ways as the parties with large stake in it writhe in agony.
2. The value will reach a resting point and become ultra-stable because people will cease to believe in speculation for infinite profit margins.