If you live on acreage, or backed up against protected wild-lands where redwoods would be appropriate, by all means have at it. If not, remember that these trees get ginormous, and wrap their roots into pipes, lift sidewalks, crack foundations, and grow into neighbors views. They can be contained, but it takes consistent trimming and maintenance (read: dollars) and if they are allowed to get big inevitably people get attached to them and a fracas erupts when a property owner needs or wants to remove them. Emotions can run wild about trees around here, on a level with fences and dogs. I have seen real estate transactions, not to mention neighborly relationships, fall apart over trees. Like bear cubs, they are so cute when they are small, but when they grow into enormous wild creatures we have a problem on our hands.
Think twice. Go visit them at Muir Woods or Big Basin, or at Strybing Arboretum in Golden Gate Park, send a check to Save The Redwoods, but if you do a small bit of research and consider the mature size of any tree you plant before you plant, you will save yourself, your neighbors and the trees a lot of suffering.
(and if it's too late for this advice, SF Friends of the Urban Forest has an arborist referral page)
