I don't do night photography with the digital too often, mostly because its a hassle with me and my camera...
...but these two, that I found on my computer are probably from 2 months back. I think I was too lazy to walk the half mile back to my place, so I waited for the bus (on a side note, I have NEVER had to pay for the bus...whether it be a "borrowed" bus pass or the bus driver just likes me, but never spent a penny on the bus...

)...and if I remember correctly, I got bored, so started to play with the camera...
Both were taken on a hand held Sony Cybershot...
The first one was taken with a lower ISO, smaller aperture, and longer shutter time...but because I tilted the camera up just that tiny bit, for probably less than a quarter of a second (as you can tell by the curve in the head/tail lights) the shot when to hell...

...and the 2nd one, with higher ISO and wider aperture, which in theory should produce a less detailed and less focused image is much better...

There is virtually no difference in pixel grain size (unless you focus on the street lamp)...and the zone of focus is well beyond acceptable (extends from beyond my knee to well past the building).
Just play around with it, and keep in mind what is best on paper/theory doesn't necessarily mean the best in practice.