One last analogy that helps understand voltage vs current is that of water pressure (voltage) and flow (current). Think of a great big water reservoir up on top of a mountain and you're at the base of the mountain (yes, this is your power supply :).
Let's say you want to design the system to put out a forest fire should it get near your house. To do that you need a lot of water flow really fast. So you make sure to connect a really big pipe down to your house. Now you've got a system with high water flow (current) that will flow for a shorter time but put out a raging fire.
Conversely, let's say you need to shoot a small stream of water over a large ravine next to your house. Now you can run a smaller pipe to build up the water pressure/voltage. The water at the end of the pipe will shoot out of the pipe, over the ravine and save the endangered species from drought.
Both systems are doing work but with vastly different design parameters required for flow/current and pressure/voltage. Which is better? Well, it obviously depends on what you want to do with the water :)
As many have pointed out, this ignores resistance, impedance, capacitance, or any other kind of system feedback/overload that can impact the system. But I hope it helps to get the general idea across very simply.
