To use a callback function you need to specify the GET parameter "json.callback" in the URL to the REST robot. For example you would have a URL like this: http://service.openkapow.com/...?resultformat=json&json.callbackFunction=myVeryOwnCallbackFunction&... Then you of course need to define the javascript funciton ...

I wanna use the callback-style functionality that Yahoo's web services and many more have. With a callback function it would be easy to use robots from withing just plain javascript.

Digg that contains just stories from specific topics and/or with specfic keywords. The demo is built using one REST robot that retreives the story topics from Digg and one RSS robot that creates the RSS feed.  This is a good example of how to use both REST robots with JSON output and RSS robots. Robots and the full source code are of course ...