For those of you not congested but facing exams, try this yogic remedy to "instantly" relieve stress:
Breathe in through one nostril to the count of three, and then breathe out through the other. This simple exercise, apparently, releases stress instantly. And if you’re suffering from a mental block, all you need to do is either breathe in through your left nostril or look up at the upper left corner of the room.
The Times of India article deals specifically with "Maths Terror," but one could hope it might also be applicable to other subjects.
Meanwhile, DownUnder, scientists at the University of Sydney have pioneered some small but effective nasal filters (worn in each nostril) to ward off the effects of hayfever and pollen-based allergies. I couldn't find any photos of the filters (possibly that's due to pending patents) but I'm guessing they aren't pretty:
"Ninety-three percent of subjects said they would wear the filters again. However, most subjects favored wearing them in private rather than in public settings."