I know about AJAX cross-domain policy. So I can\'t just call \"http://www.google.com\" over a ajax HTTP request and display the results somewhere on my site.
I tried
JSONP is the best option, in my opinion. Try to figure out why you get the syntax error - are you sure the received data is not JSON? Then maybe you're using the API wrong somehow.
Another way you could use, but I don't think that it applies in your case, is have an iFrame in the page which src is in the domain you want to call. Have it do the calls for you, and then use JS to communicate between the iFrame and the page. This will bypass the cross domain, but only if you can have the iFrame's src in the domain you want to call.