From looking at this interview of David Hayter at E for All, well if you look at 1:32 I was in the line right before you get to the bleachers, and I remember seeing some guy signing shirts, although I didn't know it was him. :-\
Feel free to smack me upside the head right now.
Moral: at a convention as awesome as E4All, do EVERYTHING no matter how insignificant you think it is.
At least we can both agree on something.