When it comes to hostels I have no idea but I hear people talk about the Generator so try there maybe? Travel Punk has a page for hostel searching though which should be a good help.
Your list seems great in fact the only thing I would add is perhaps getting a drink and seeing the live shows at Covent Garden. Its not just music either-one time I went and they had this guy escaping from chains and jugglers and people who will do portraits it can be quite the experience!
I have been to: Canada, USA, Iceland, Britain, France, the Netherlands, Belgium, Spain, Poland, Germany, Sardinia, Switzerland, China, Argentina, Brazil, Chile, Uruguay and Morocco.
Do to list: [color=blue][color=black] Australia, New Zealand, Austria India and Bolivia.
[color=blue][i][font=Verdana][color=black]"I'm just another stranger lookin' for the promised land"