In terms of low light, you can always do a long exposure with a pocket camera, if it will let you disable the flash and you can hold it fast with a tripod. You may have additional noise, but hopefully not any worse than you'd expect during the day.

I had to do a little digging around to find some good example photos. First, here's an available-light photo taken in a lava tube in Hawaii with my old Canon G3. This was a one second "raw" exposure (ISO 50), pushed two stops using Adobe Camera Raw without any more than the usual noise reduction settings:



Here's a 1:1 pixel detail blow up:



Certainly, there's some noise but nothing that renders the image unusable. Now, for contrast, let's look at a what a D-SLR (my Nikon D70) can pull off. Here's a shot of the Vancouver (B.C.) skyline at night. Six seconds long, f/8, ISO200, with the camera braced against a balcony.



Here's the 1:1 pixel detail:



Certainly there's much lower noise and greater detail, although I had to work it over with Photoshop to get the right exposures for different parts of the image. I'd say the moral of story, for whatever it's worth, is that you can get good pictures with anything, but you can always do better with fancier gear (if and only if you can be bothered to haul it around with you).