The graininess comes from the high iso level that the camera selects by default for dark situations. Concerts can often be photographed at lower iso levels because there is a lot of light up front. Point your cam at your TV from across the room in the dark (tv works great because it is bright and colorful in the dark, so you get a good contrast) and then press menu on the phone and try the different iso levels to see the difference. The higher it goes the grainier it will be. In low light situations the cam will usually use a higher iso to allow for more detail, but at the cost of some grain to the pics. I have found the dinc2 not to be the best at judging the correct iso speed at night, but I still find the camera to be very good. Better than my Droid X camera by far.
Gettin it in South Africa - YouTube Video at the beginning taken with the front facing camera, all other video and pictures taken from the back camera at full power
Here's a couple I took and thought I'd share. I think they came out so clear and crisp, hope someone enjoys them. And don't worry, the baby sea lion made it back out to sea.