Sadly, The Live Feed is no more on Freeview. I have Freeview and have just learnt that it is no more due to Film4 starting. The live stream is still available on Sky and NTL though. No good for us freeview viewers!
The following quote from Wikipedia: "Freeview viewers were previously able to view live streaming by pressing the red button while watching E4 and 'LIVE' is displayed. This redirected the viewer to channel 305, which required More 4+1 to be discontinued to allow for the transmission. However, as of 17th of July this feature was removed in preparation for a free version of Film Four due to air from 23rd of July." (link:
http://en.wikipedia.org/wiki/Big_Brother_(UK) ... found under 'Live' heading.)