To me it seems beyond question that fundamental research is justified by the utility of the resulting technology, but it is a matter of time. In fact I tend to think in terms of 100 year increments before the utility of scientific advances are fully appreciated: Newton's work made possible the industrial revolution, which came about a century later. Maxwell published in 1864, and it was 100 years later that most Americans were getting their first television. The foundation of the information age that we enjoy today - that is changing the world in ways that we can only begin to fathom - was layed in the early nineteen hundreds by the fathers of quantum mechanics. And it would appear that Einsteins quanta and the photoelectric effect will finally result in cost effective and practical solar panels almost exactly 100 years after he received his nobel prize.
If we were to make a list of the top 100 most significant advances in technology that affect our lives today, how many would not be rooted in pure research? And beyond the long term benefits, as noted in Zapper's response, we often do see the benefits in two or three decades. For example, the first working LASER - then called a solution in search of a problem - fired only 48 years ago, and the benefits from it were seen almost immediately.
It is not utility that must be demonstrated, it is a question of the value placed on the future of humanity. Is it worth investing in the future of the human race? Do we owe the effort to future generations to continue the grand tradition of discovery, or shall we merely profit from the efforts of those who came before us? How much value do you place on your children's future?
