I really like the idea of this tool, but have failed to get it working well.

I use phoenix as my miner on ubuntu 11.04.  I have tried a couple different web hosts including my own ubuntu 11.04 box, and I have the following symptoms:

1. lots more stale shares than when connected directly.  long polling does not seem to work with phoenix through the proxy but works fine when connected directly.
2. phoenix miner *hammers* the web server with requests to index.php.  Something like 10-20 requests per second as seen in the apache access.log.  When connected directly and observed with tcpdump it behaves much more normally (1 request every 5 seconds or so).
3. lower than normal hash rate when using the proxy.  I suspect this may be because the miner is so busy doing #2 as fast as it can.

I also tried poclbm on my Mac and it had similar problems with stale shares.  I did see an occasional LP message, but not frequently enough as compared to blocks being found in the network.  I also regularly got errors about "NoneType" not being indexable.

From this thread, though, it sounds like some people are having great success with it, so I wish I knew what to do differently.