10 Important Differences Between Brains and Computers

Difference # 1: Brains are analogue; computers are digital
Difference # 2: The brain uses content-addressable memory
Difference # 3: The brain is a massively parallel machine; computers are modular and serial
Difference # 4: Processing speed is not fixed in the brain; there is no system clock
Difference # 5 - Short-term memory is not like RAM
Difference # 6: No hardware/software distinction can be made with respect to the brain or mind
Difference # 7: Synapses are far more complex than electrical logic gates
Difference #8: Unlike computers, processing and memory are performed by the same components in the brain
Difference # 9: The brain is a self-organizing system
Difference # 10: Brains have bodies
Bonus Difference: The brain is much, much bigger than any current computer

more at http://scienceblogs.com/developingintelligence/2007/03/why_the_brain_is_not_like_a_co.php