I agree with all who said snot rockets are it! For awhile I relied on the nose-wipe panel on my gloves, which is okay except that when it's cold, my nose gets chapped right quick.

Yeah, snot rockets are ick...but once your technique is mastered they're the best solution, especially if no one's around.

Just don't be like the dudes (they're always dudes) that I see standing around the parking lots, STILL blowing snot rockets even though they're standing still. Now THAT is gauche!