Charity? Good or Bad Thing?

Interesting to see what the global Tsunami Appeal will do to the income of all the other major charities.
There is only so much disposable income to go round. and occasionally, people are moved to dig deeper. Or more people are moved to dig for the first time. But over the long term, the money just moves about. The overall sum doesn't increase.
So what exactly IS the role of Charity in this situation? Might it be a BAD thing in that it might actually cost lives somewhere else?
Shouldn't this be a political matter, like space exploration or nuclear power? Should people be now told to start giving money somewhere else as governments would write a collective blank cheque?
Might not the sudden disappearance of all this disposable income into what is in effect a very long-term investment actually be a depressant on a global financial market reliant on short-term return? That money is now spent. It can't buy any more i-Pods.
Is the current trend towards global mass-media appeals a symptom of a deep problem with the political system in that we are having to do the job of the politicians? Or might these events, with their reliance on global telecommunications and sophisticated internet registering systems, even be a forerunner of a future cyber-democracy?
A world without politicians in which our taxes are deducted according to a constantly monitored set of fluctuating Lifestyle Vs Responsibilty Parameters. [[there goes one New Year's resolution]] A society based on Cyber-Charity, with Google as its Civil Service and Microsoft as its public transport system.