Well, once you're sick, there's not much you can do except wait it out. In order to prevent getting sick in the first place, I drink a lot of tea, take Vitamin C supplements and wash my hands whenever I return from outside. Before I had kids, I got sick maybe once every two years or so. Now, that I have kids who pick up everything under the sun from their respective schools, I tend to get sick about once a year. When I do get sick, I try to drink as many fluids as I can to flush the virus out faster (I find Gatorade to be particularly effective in boosting my own immune system). If the sickness lingers, though, sometimes you develop a secondary bacteria infection that takes advantage of your reduced immune system by the original virus, so an anti-biotic might be in order if you don't get better after 7-14 days (most viruses run their course within 48 hours).