How to setup a Speech Recognition Server?

Question

How to implement Speech recognition at server side (please don't suggest HTML5's x-webkit-speech, javascript etc) ? The program will take an audio file as input and with sufficient accuracy provides the text transcription of audio file. What are the options I can use ?

I have tried implementing Sphin4 with Voxforge model but the accuracy is so poor (their may be also some problem in my configuration, I am still trying to learn it). In one post I read that when we use <input name="speech" id="speech" type="text" x-webkit-speech /> the input is sent to an external server and that server than does the recognition and sends the data back to the browser.

How can I setup that server ? Any existing open Source server would be also useful if it can recognize English sentences with minimal error rate.