Whether it's a sinus infection or a cold or other virus, try one of these:
Why yes, I did finally come down with my kids' virus, what made you ask? :) (Actually left the house this morning without trying any preventative measures, knowing I was getting the crud. By 5pm I was running a temperature, so I headed home and took Ibuprofen and made my first attempt at using oregano to fight a virus. So far, I'm impressed, but we'll see how I feel in the morning.