How this is worth taxpayers' money, I have yet to be convinced.

First of, Hyugens was paid for out of European tax dollars, so it's pretty much a freebie for us. But as for why we should spend ours on space, I's point out Near Earth Asteroid 2004MN. It's going to miss us in 2029, but we aren't always going to be so lucky. Remember: The dinosaurs are extinct because they didn't have a space program!

Cybrludite is right. There are other aspects to be considered as well. If you are concerned about the possibilities of overpopulation then the expanded living areas that space colonization would bring is definitely a plus and probes are useful in telling us what is there to work with. Solar Power Satellites would be a useful supplement to our energy budget. Asteroid mining would provide useful minerals and terraforming materials. Lunar regolith could be a useful crop fertilizer the way guanno from Peru was. If you need pragmatic reasons why Space development is A Good Thing they really aren't that hard to find. ^_~

I guess of all the thoughtful responses, I really have nothing of note to add, save this old hoary notion: of what use is a baby?

Explaining to someone what the value of science and technology this soon after the dawn of the 21st century is, one some level, fruitless.

Either it makes sense, or we can simply rehash all the existing arguments about the notion that perhaps, just maybe, expanding the horizons of human knowledge might not be, as you tend to suggest, an idle pursuit or the a dilettante's distraction.