In addition to plenty of turkey, <A HREF="http://news.zdnet.com/2100-1009_22-6136901.html?tag=nl.r23660">a record amount of spam</A> will be served up this holiday season. Mass emailers traditionally bump up their activity as the year winds down. But this year, the amount of junk messages could be unprecedented, companies that make spam-busting tools say. And senders of unsolicited ads are already celebrating the close of the harvest season and the approach of Christmas.