I've dealt with sinus infections since I was young. I used to end up with antibiotics quite often, but haven't had to take them for about 15 years (although I still get sinus infections). A couple years ago, Seth Godin wrote about a nasal irrigator that he uses (http://sethgodin.typepad.com/seths_blog/2009/10/sinusitus-relief...). At $100 or so, it is an investment. But, it has helped me immensely. He also mentions drinking two tablespoons of apple cider vinegar every day.
I don't like to take antibiotics as it is not good for stomach flora. When i feel a sinus infection coming on i use a neti pot to rinse the gunk out of my nose. Seems to help. silver sinus also works real well for me and saves me a trip to the doctor. (Who was going to prescribe me antibiotics anyways!) LOL.