For those who still buy a real Christmas tree, disposing of it can be a real pain once Christmas is over. In New York City however, the problem is dealt with sustainably by the City's Department of Sanitation.
Every year since 1993, the Department of Sanitation in New York City have collected around 2,500 tons of Christmas trees once the Christmas period is over. They then arrange for the trees to be ground into wood chips to be used as mulch or as a bulking agent to mix with yard waste to make compost. The mulch that is produced is used in parks, playing fields and community gardens. However, residents with their own backyards can take the mulch for themselves at organised "mulchfests".
And, whilst there are drop off places to take old Christmas trees to, the Department of Sanitation will also collect Christmas trees, stripped of lights and ornaments, from the curbside on designated days in December and January so that they can then be ground into mulch.
There are also similar schemes in the UK. To find out whether your Christmas tree can be recycled and turned into wood chippings to be used in an environmentally friendly way in your area, see http://cedr.ec/18z or contact your local council.