Recently was developing small flash widget witch can be placed on any subdomain, but data exchange goes with another site. Main thing is that the domain from witch comes initial data have to have a crossdomail.xml file to work properly.

crossdomain.xml file have to be putted in root directory of domain. Example of crossdomain.xml file.

<?xml version="1.0"?>
<!-- http://trashmail.lt/crossdomain.xml -->
<!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
  <allow-access-from domain="*" />
</cross-domain-policy> 

Example of file location http://trashmail.lt/crossdomain.xml. From now any flash that makes request's to trashmail.lt will work properly.