The best results from the S220 come at ISO 80 and ISO 100. As soon as you go up to ISO 200, detail and sharpness are on steady decline. The marks on the ruler are barely visible from noise reduction at ISO 400. Unfortunately, the camera seems to love this sensitivity when its in Auto ISO.
There are three remaining sensitivities above ISO 400--800, 1,600, and 2,000--that are really not usable for prints. However, if you're in low or dark lighting, you'll be able to capture photos. Just don't look at them too closely.
Before you write the S220 off completely, it is capable of taking good photos. This was taken at ISO 80 with the camera set to Program Auto mode. If you're into macro photography, though, this probably isn't the camera for you since you can only get down to 4 inches from your subject. The 10-megapixel resolution does buy you some room to crop in, such as in this picture.
Shot using the Landscape scene mode, the S220 went with ISO 400 likely because of the dark background. More importantly, if you were to print the photo at the center full size at 9x12, you would see a lot of problems: blown-out highlights, purple/blue fringing, and mushy, smeary details that make the result look more like a painting than a photo.
All of that said, when printed at a typical size like 4x6 inches, the only thing immediately noticeable are the blown highlights and a general lack of sharpness--neither uncommon for low-end point-and-shoot cameras.
Part of the S220's photo issues stem from lens distortion. Nikon includes a setting to correct for barrel and pincushion distortion. On the right are photos taken with the distortion control off. The photos on the left are with it turned on. Applying the correction takes the camera an extra second or two to process, but it's effective.
Unfortunately, Nikon doesn't correct for fringing. Again, this is typical of point-and-shoot cameras, but the S220 produces an above-average amount of it. Best advice: avoid high-contrast targets and backgrounds such as the bright light and trees in this shot.
Colors produced by the S220 were a little wonky. Greens and reds weren't exactly accurate, but for the most part were pleasing. Blues and violets seemed particularly tricky for the camera, though. (See the next slide for an example.)
OK, so this verbena would be a tricky color to capture accurately for any compact camera, but the S220 definitely struggled with it. Below it is the same flower taken with a Nikon D60 and is the correct color. Of course, the D60 is five times the S220's price and not a pocket camera; the photo is more for reference than direct comparison.