One of the good high-level programming model introductions to Javaspaces is available behind a registration wall. I was handed the PDF but since it is copyrighted yet free, I'm uncomfortable posting it for you. I'd recommend you register and get it if you are curious about a simple model meeting a common need where Javaspaces provides much less effort than, say, JMS.
I'll call it "Resilience and the Error Hospital" while the actual title has more buzz words (e.g. SOA) and no direct URL.