you can upgrade them. You do need to find out what the board will support though. They are simular to Desktop CPU's except the heatsink is not so big. If you can, post your laptop model information and I will see what I can find for you...
I beg to differ. On the contrary you can. It's just harder than on a desktop.
Some laptops will only support a processor up to a certian GHz. For example, I currently own a laptop which will support a processor with a speed up to 3.06 GHz and nothing more.
You would have to remove the keyboard, then the heatsink & fan assembly and take your old processor out, then put the new one in and put everything back together again.
Not sure about Toshibas. Check out their website for any information on your laptop model. I believe you can only use Intel processors in Toshibas.
-Silent Fear
EDIT: Why does everyone else get their replys in before me?