JSON has been the subject of a few domino blog entries lately. Jake Howlett's
XML is Dead. Long Live JSON article was the first I read. In the comments, Patrick Niland suggests a creative way to avoid using an agent. Jake then adds that appending a 'null' to the text around the JSON data in $$VT may work too. I tried it and it works well.
Instead of using a view template, I use a page with an embedded view. It accepts the &count= parameter and that's all I need for my map. The page is set to "Content-type: Other text/plain". And the embedded view is contained within opening and closing square brackets. A "null" precedes the closing bracket to handle the leftover "," from the last view entry.
If you’re operating on the data immediately after receiving it, like to .sort() it, then you may need to .pop() the last null entry off the stack/array
Anyway, the demo, yet another google map, is available for viewing and download. It shows service data on a US map and allows users to click to open a ticket. The display table in the right pane is sortable. And the data refreshes at a user-defined interval. As old Jake suggests, the entire app is much easier with JSON than with XML.