Touchpad is moving the cursor when I am typing.

When I am typing an email, I sometimes unintentionally touch the touchpad with the palm of my hand causing the cursor to jump to a different location in the document. So I have to edit the text quite often.

Is there a way to:

a.) Have the touchpad understand that I am typing and not touching the touchpad :-)

b.) Reduce sensitivity on the touchpad

c.) Temporarely disable the Touchpad with a keycombination

d.) Any other solution I have not yetthought about other then learn to type in a proper way  

Thanks for any advice, tips or hints,

Thanks

Peter

(Dell Precision M2300 with Windows XP 64 bit)