DES PLAINES, Ill. -- "Be safe everybody," a Kmart worker instructed customers here as they filed into the store at 6 a.m. on Thanksgiving Day, looking for deals on items such as headphones and clothes. But the instruction may have been more of a formality. Once the dozens of people lined up outside the store were inside, they calmly browsed the aisles and compared prices on towels and toasters to those listed in the circulars they had brought along.