All Saints night, or Deads' night is maybe one of the most magic celebrations here in Mexico. It is a remain of indigenous traditions, mixed with catholic believes. Basically, people set an altar at home, where they put food and drinks, candles and sometimes religious images or pictures of their friend or relatives who have passed away. Supposedly the souls of the deads come during the night and eat the meals. Some people refers that when they eat the food after the celebration, it has no flavor: deads had taken it away.
In differents parts of Mexico, the celebration has different variations. In some places, it is a tradition to set the altars on the graveyards, as it is done in Janitzio, an island in Michoacan. (pictures are from there). Normally, we have this celebration on November 1st and 2nd. Suppossedly, on the 1st we remember dead children --some people call them little angels--, and on the 2nd the rest of our deads. Is nothing to do with Halloween, because the general belive is in Mexico is that on those days spirits of deads visit their loved ones, but not to scare them or anything. (But in general, may people in Mexico also belive in ghosts, spirits and so on, and the country is full of histories about them.)
This is maybe my favorite mexican tradition, because since the ends of October you can see cempasúchil flowers (the orange ones) in the markets, the downtown (even in Mexico City) has an special incense smell, sugar skeletons are sold on bakeries and groceries, the weather is not yet so cold, but normally windy... And also we have an amazing tradition of art with skeletons made with different materials like paper, mud, chocalate, sugar...
The celebration has became more important in recent years, maybe because of folk, tourism or who knows why, but it is still a unique tradition.