Please help with advice on two webcams..!?

-http://www.logitech.com/en-gb/webcam-com鈥?/a>



or



http://www.logitech.com/en-gb/webcam-com鈥?/a>



I have an acer laptop, with windows vista.. if that makes any difference.



I'm going to use it for still shots, and video calls on msn :)From the specs, the 270 does HD video and the 170 does not