The following code, copied from the Facebook documentation here, is not working for me in Chrome.

<div id=fb-root></div>

<script src=http://connect.facebook.net/en_US/all.js></script>

<script>

  FB.init({

  appId  : 'YOUR APP ID',

  status : true, // check login status

  cookie : true, // enable cookies to allow the server to access the session

  xfbml  : true  // parse XFBML

});

</script>

In the Javascript console I get:

Uncaught ReferenceError: FB is not defined

I'm not having any problems with the SDK in Firefox or Safari, just Chrome.