My girlfriend likes to watch Oprah, and occasionally Oprah has a doctor on her show talking about different health stuff. Those are probably the best episodes (the debt diet ones are good too). Earlier this year they featured a Neti Pot, which is a device for rinsing your sinuses. Supposedly it's benefits include prevention of common colds, and alleviating cold symptoms like post nasal drainage, and coughs caused by post nasal drainage. I had a cold earlier this month that lasted about 2 weeks (so maybe this thing doesn't prevent colds), and I took that as an opportunity to try out the cold-improving features of neti pots.
Sometimes when I have a cold, it's hard to get to sleep because of all the coughing, so I decided to use the neti pot every night right before bed. It worked pretty well (although the stupid cold still lasted 2 weeks). Most importantly it was kind of cool in a little-boy kind of way: i.e. it's gross, but the grossness is half the fun.
I also figure this is probably a healthy thing for my family members in Mexico to do in order to combat the effects of that nasty air-pollution.
There are a whole bunch of video's on YouTube featuring instructions. This one right here is pretty good.