Hooking into DataSift feed

[shocks]

Hi

I'm completely new to HTTP with AsyncSocket, not to mention only have
2 weeks iOS dev under my belt so please excuse my ignorance. I'm
trying to build a proof of concept iOS app which will consume Twitter
data originating from DataSift (http://dev.datasift.com/docs/streaming-
api/http-streaming). How would I construct my GCDAsyncSocket request
to achieve this? The URL I need to call is is structured as follows:

http://stream.datasift.com/<hash>?username=<username>&api_key=<api_key>

Thanks for any input or a pointer to the documentation I should look
at.

Ben