Every year, one of my co-workers puts a Festivus pole in the office. It's an actual aluminum pole, and he sticks in in the intersection between four cubicle walls. It remains there, unadorned, with no distracting tinsel, until after the holiday season.
The Airing of Grievances doesn't happen only during Festivus, either. No. We keep the Festivus spirit in our hearts all year round.