>Is there an easy way to apply this globalization setting to an entire web application? If not, is there just a simple way to tell currency columns in a datagrid to format that way?

Sure. Once you apply a globalization setting it becomes permanent on the current thread. In a Web application you have to do this on every hit in Application_BeginRequest() for example as ASP.NET resets the localization and globalization settings to a default on each hit (to the setting specified in web.config).