Strunk and White say that that adding an apostrophe and another “s” is the way to go (e.g. “James’s bicycle”) aside from specific exceptions, such as ancient proper names like “Jesus.”
I’ve found it quite rare for people to actually adhere to this rule, though. I see the supposed error repeated nearly everywhere I look.
Has this rule changed, or do people just ignore it? It’s still present (and, in fact, is the very first rule on the first page) in my copy of the fourth edition (1999) of Elements of Style.