Overclocking on a laptop is much more difficult and risky than on desktop. The reason is heat management. Usually laptops and small netbook computers can only manage a small amount of heat due to space limitations and small fans used inside. Hence if you overclock your laptop you are pushing its limits a lot. I am writing this on an overclocked laptop (Acer Aspire 3000, Sempron 1.6GHz @ 1.8GHz) but as you can see the difference is not going to be huge. But it still helps my desktop being just a bit more fluid. Mind you it has made the laptop much hotter and quite more noisy (the fan spinning up more often to help it cool down) and it also affects battery life a little. Since i use it on a desk though i do not really mind and i overclock it on a daily basis (no games, work PC).