With more and more talk about JSON coming up, there are blog posts like Randy Boland's latest, his brief look at this technology and his it can interact with PHP.
I talked with one of the guys at work about writing a function in PHP that would take an array and generate the appropriate code, until I came across the (seemingly de facto) "official" JSON page. He's got references there for pretty much every language you'd expect to do web development in (and a few you wouldn't) - including JSON-PHP, which does exactly what I was going to.
John first mentioned JSON about a month ago, but at the time I had no inclination to look into it and find out if it was something I could use. It came across my radar again today thanks to a Particle Tree article that I never finished reading, but that's not important. The long and short of it is that JSON is really just a fancy name for eval-ing JavaScript objects - one of those "why didn't I think of that" kinds of things.
He also notes that combined with the power of the Prototype Javascript library, a simple, Web 2.0-ish application can be made in no time flat...