Hi B.,
I share your pain. . .my 6-month old has been that same way since he was born. I actually called the doctor in hysterics one day, because you're always told to nap when baby naps. No one's had any advice on what to do if your child DOESN'T nap.
A few of the other ladies sound about right with their suggestions for Dr. Weissbluth's book. While it didn't work to a tee with my baby, a lot of his suggestions are dead-on and extremely helpful. That man defintely knows what he's talking about.
If it helps, my doctor said that as long as your baby is sleeping well at night, and isn't showing other symptoms like not eating well, lack of dirty/wet diapers, inconsolable, etc., there shouldn't be a problem, and actually that phrase, 'sleeping like a baby' isn't entirely accurate for everyone (obviously). I know it's easier said than done, but try to take it in stride, and if you haven't already, you'll find a routine that works for both you and your non-napper baby (we finally did! ;-).
Best of luck to you!!
K.