Re: how do i change that icon?

Essentially, look for the line icon.image and replace it with whatever
you want.
icon.image = "http://labs.google.com/ridefinder/images/mm_20_red.png";

You can point it at any image you want to. BUT, some browsers won't
scale the image even if you tell them to.

Checkout the API documentation at:
http://www.google.com/apis/maps/documentation/#Creating_Icons
for more info.

good luck