This was actually a session I attended at BarCamp – in fact it was presented on my laptop. ;)
However, Alan Taylor already had the guts of the session put together as a blog post, so rather than try to reconstruct my notes, I’ll just link to the original.
Good clear overview of how to use xslt to convert what Amazon’s web services return directly to JSON – that way you don’t even need to do any server side processing- the client js can call directly from Amazon and let them do the transformation.
KOKOGIAK – Consuming Amazon’s Web API Directly with Javascript (via JSON and XSLT)
