Zoom lenses are a great invention. If you can't control your distance to the object, simply adjust the focal length of your lens. Even better (it seems), zoom ranges have gone up considerably over the last few years. Instead of the 3x zooms (e.g., 35-105mm, 70-210mm) of previous lens generations, today's lenses have an 7x or even higher range (e.g., 28-200mm, 35-300mm).
As with everything, there are also disadvantages. A modern 3x zoom is comparable in quality to a prime lens, but will cost you dearly! An 7x zoom, such as the popular 28-200mm will require a complicated lens design with numerous elements inside. The more elements, the more problems. There is more light loss (largest aperture might be 5.6 when the lens is fully extended), and there is frequently a lack of sharpness and resolution. Furthermore, these lenses will be much more prone to flare and reflections within the lens when you take pictures against the sun. Furthermore, lower priced zooms don't have a fixed aperture, but require more light at longer focal length.
(c) Christian Wagner, 2001.
Vivitar 28-200, 3.5 -5.3 lens. I bought mine from eBay for less than $50.