Whoa, you're just way off base here. You can take a long exposure and avoid star trails depending on a couple of factors, primarily the focal length of the lens. The longer the lens, the less time it takes to start seeing trails. The wider the lens, the longer you can take. I've taken up to 45s exposures with a 20mm lens on a DSLR with no trails. Since most lenses on camera phones are typically wider angle, the limiting factor is having a support to hold it for longer exposures.
