Why do we close our eyes when we sneeze?
Must be something to do with Home Depot. Makes you wanna jive and boogie, perhaps?
I think swinging your arms has to do with inertia - it helps power you along a bit. Otherwise dead, non-moving arms will create wind drag and slow you down!
Well, actually, I made that up, but it sounds good!
Cheers
Mick
edit: Boy, some ppl take this question seriously! Look
here and
here!