Another thought, that often enters my mind, "What if by mining, at or above the cost of electricity, I'm just buying BTC at the cost of consumption? Every other form of revenue has energy costs, why is media harshin' me? Not trying to sound over-Libertarian posed, but I find myself hard-pressed to consider what my energy costs are, when driving to work and working on PCs anyways, as a systems analyst...
I don't think you should feel bad. When bitcoin uses too much energy, a more energy efficient version like ppcoin will outcompete bitcoins.
You are helping advance technology and the energy issue will be solved. It just might be that it won't be called bitcoin, but it will be crypto currency.