the weight that you really want to get rid of is unsprung weight. So you should really try and find some light wheels and tires. They say taking one pound of unsprung weight off is like taking eight pounds of regular weight off.You could go as far as getting light weight lug nuts to go with the lighter wheels and tires, every little bit helps. Then there are the things everybody else has been talking about:
CF hood
CF trunk
CF fenders(even though i can't imagine normal fenders weight that much)
back seat
Spare and tools
carpet
You could strip the sound deadening and tar( this might be going a bit far)