Userscript to disable Google Maps scroll zoom in Google Chrome.

disable_google_maps_scroll_zoom.user.js

// ==UserScript==
// @name           Disable Google Maps scroll zoom in Google Chrome
// @namespace      http://henrik.nyh.se
// @description    Disables Google Maps scroll zoom because it's unusable with Apple's Magic Mouse. Confirmed to work in Google Chrome.
// @include        http://maps.google.com/*
// ==/UserScript==

// Adapted from the Safari extension by Mario Tausch/Tiago Rodrigues (https://public.me.com/ix/mariotausch/dev/index.html)
// via http://www.leancrew.com/all-this/2011/05/the-google-maps-scrollzoom-confusion/.

var noop = function(e) {
  e.preventDefault();
  e.stopPropagation();
  return false;
};

var children = document.getElementById("map").childNodes;
for (var i=0, l=children.length; i<l; i++) {
  children[i].addEventListener("mousewheel", noop, false);
}