Looks like Seth Godin shares my attitude towards focus groups. Money quote:
"What focus groups can do for you is give you a visceral, personal, unscientific reaction to little brainstorms. They can help you push something farther and farther to see what grabs people. But the goal isn't to do a vote or a census. Any time your focus group results include percentages, you've wasted an afternoon."One-on-one interviews, surveys, and ethnographic studies are usually more informative.