Transfer data from Android app to external database

I need to send some data periodically from an Android app to an external SQL server. I was thinking about creating a WCF service for this purpose which would receive a JSON object or perhaps XML.

Is this a good way of doing this? Anyone have a better idea?

Works for me. In one of my projects i'm using a WCF service which offers a RESTful interface to a database. Serialization format is JSON. No need for any external libraries, no nothing and it's easy to implement on both sides. There are thousand of info around the web about both topics.