Nice work. And there's other implementations too on the project web page: https://sites.google.com/a/chromium.org/dev/spdy. Seems all google sites are using SPDY for ssl now; that is evidently the lowest hanging fruit for speed gains.
You can see it in use in chrome by visiting chrome://net-internals/#spdy
No idea when it's going to be supported in any browser besides chrome, though ..
Python implementation of a SPDY server: http://github.com/mnot/nbhttp/tree/spdy
Java imlementation of SPDY client/server: http://svn.apache.org/repos/asf/tomcat/trunk/modules/tomcat-...
Apache module for SPDY: http://code.google.com/p/mod-spdy/
Ruby SPDY: https://github.com/igrigorik/spdy
node.js SPDY: https://github.com/donnerjack13589/node-spdy