When I visited my friend in Kentucky she took me to the local cemetary and it was HUGH. It was a fascinating place though, there were some fantastic gravestones, there were even some crypts. And the military section was in such straight lines I don't think they were 1mm out! So BOO is probably right that they aren't as short of space as we are. I do remember seeing something on Friends though about Phoebe having a friend who owned a crematorium, so they do exist.
The practice is growing here in the U.S., not by leaps and bounds since traditional burials are still the first choice. But lots of people at least discuss it now. Additionally, except in larger cities, crematoriums are generally not available. Here, where I live in the western U.S., the nearest one is about 150 miles away... but then almost everything is 150 miles away!