I think the gpu can be overclocked, but im not sure if that was only for the older ones with the ati radeon graphics. I wouldnt personally want to overclock the cpu on a laptop due to thermal issues. Overclocking ram will yield very litttle performance gain and i dont think you will get too much of a performance gain from that.
Edit: i think most laptops are locked from overclocking cpu and ram in bios anyways except i think for the laptops that ship with the intel extreme mobile chip.