'Tis the season for agency holiday Web sites. Last year's highlight for me was R/GA's Tattoo Santa. Disturbing. This year, Minneapolis shop Colle + McVoy is up first. It began with a run-of-the-mill holiday card, which arrived at the office with some 3-D glasses. The card directs to Snowdin.com, a Flash gaming site with a pretty impressive 3-D experience. Visitors can menace a snow creature, pilot a blimp through a winter wonderland and deliver the evening paper to "Avalanche Alley."