Don't trash your printed map yet
The rise of online directions and the frustrations with and shortcomings of them are covered in this New York Times story (registration required):
MapQuest, a subsidiary of AOL, is by far the most popular such site, with 22 million visitors a month. Every day, the site produces 10 million individual maps and sets of directions.
...Joel Minster, a senior vice president at Rand McNally, said online maps have not hurt the company's business. "As a matter of fact," Mr. Minster said, "what we're seeing is that people are more comfortable with maps and come to expect them more." And what does frustration with online maps drive people to do? "They go buy a real map," he said.