I think this is a required feature for developing HTML5 webservice clients

For the readers: Please note that this is not required if you package your app with Phonegap or other frameworks.

See: http://wiki.phonegap.com/w/page/16494770/FAQ (AJAX question)..

Q. I want to create an application for phonegap to access externally deployed web services via AJAX. How can i resolve the issue with the
cross-domain security policy of XmlHttpRequest?
A. The cross-domain security policy does not affect PhoneGap applications. Since the html files are called by webkit with the file:// protocol, the security policy does not apply.
(in Android,you may grant android.permission.INTERNET to your app by edit the AndroidManifest.xml)

The github submission I attached was created for testing a Moodle HTML5 ws client prototype. It could need a bit of polishing, but it should not be far from final version.

I have to agree, this would be a useful addition to Moodle's web services.

Jerome - github submissions looks good but shouldn't the Content-Type be "application/javascript" for the jsonp content type?

Hi Nathan, I don't know, I didn't ask myself this question as token.php already return json and it worked like that. But it's a good remark.

I will not be able to work on this issue in the immediate future. In order to create a truer sense of the state of this issue and to allow other developers to have chance to become involved, I am removing myself as the assignee of this issue.
For more information, see http://docs.moodle.org/dev/Changes_to_issue_assignment