One of the old regulars in a pub I worked in still remembered food being put outside on Halloween in the village he grew up in. He told me that Halloween used to be the equivilant of New Year's Eve in pre-Christian times in that it was the death of the year. Not sure if that's connected to Samhain, I don't remember him explaining it further.

Oh and they used to bring a gift of bread and salt over the threshold when someone moved into a house.

Yes...Samhain was the Celtic New Year.

Or, alternately, Samhain is an evil demon (as widely described by confused Christians...)

The American Plains Indians, marked the years from first snow to first snow, which would put the new year about the same time.;)
http://wintercounts.si.edu/html_version/html/index.html