Links to Web Proxy is a WordPress plugin by michaelmarus ans trabaria that can create a Web proxy for links in your WordPress CMS. This can be useful for Cross-Domain calls. The plugin also fixes most orginating content character encoding problems.
The author says this plugin to create Web proxies for ArcGIS MapServers and to clean invalid characters from feeds.
Download: http://wordpress.org/extend/plugins/links-to-web-proxy/