You BUY ONE. You GET ONE FREE.
Also, OP should do Aikido - no stance and thus no clue to the attacker to take advantage of.
Boxing stance!
I go straight into my boxing stance.
I commend your willingness to stand and bang, how ever you were probably dealing with someone suffering from a mental illness, so take that into consideration.
Old School 'Boxing Stance' as demonstrated by Sherlock Holmes:
http://www.youtube.com/watch?v=OjKXFBkNE10&feature=player_detailpage#t=90s
Massive LOL
Did the OP actually get spat on? Thread title is misleading.
I stop and looked at him and low and behold another spit ball winging its way to me, I manage to just slip out of the way just in time.