As stated in this article by Microsoft you need to host a xml config file on the webservice from which you application was downloaded to allow the application to make cross domain calls.
Are there any workaround for this? My silverlight application can be run OOB or possibly hosted on some random webserver (where a crossdomain.xml or clientaccesspolicy.xml cannot be placed).
The calls i need to make from the silverlight application are calls to various json webservices (using the SilverlightServiceClient from ServiceStack), but i do not know the URL in advance.
Cheers!