The reason this posting lands in the PHP category is that I want to have a playground testing PHP applications with mod_spdy. Currently (and probably also in the future), this machine uses mod_php instead of php_(f)cgi(d) - this is not recommended for interoperation with mod_spdy. To test the real-life impact of the possible thread safety issues, I am using my private pages as a sandbox.
He has two other PHP-based applications running with the accelerator - a Gallery3 install and a WordPress site. SPDY ("speedy") was released by Google and is similar to HTTP but with a focus on minimized latency and heightened web security.