Concurrency in Python references

After reading a paper on Active Objects, I decided to go back and read the various threads on concurrency for Python. In terms of web pages, there were references to POSH and a tutorial on Kamaelia. In terms of PDFs, there was "C++ and the Perils of Double-Checked Locking", "Concurrency Among Strangers", "Composable Memory Transactions", and a paper on Kamaelia called WHP 113 from BBC R&D (can't copy from the PDF since it is protected).