Below is the list of all the organisations to whom the ICO have written (here's the form of ICO letter) to ask about their cookie law compliance, an interesting mix of private and public sector!
Acumen Professional Intelligence Limited
Amazon.co.uk Limited
AOL (UK) Limited
Apple (UK) Limited
Argos Limited
Associated Newspapers Limited
Automobile Association Developments Limited
Barclays Bank PLC
BBC News
BBC Radio 1
BBC Sports
Belfast City Council
Betfair Limited
Boots UK Limited
British Airways PLC
British Broadcasting Corporation
British Sky Broadcasting Limited
Channel Four Television Corporation
Department For Transport
Deputy Company Secretary
Derry City Council
Direct Line Insurance Plc
Domino's Pizza Group Limited
Dumfries and Galloway Council
easyJet Airline Company Limited
Ebay (UK) Limited
Everything Everywhere Limited
Facebook UK Ltd
Giving.com Limited
Google UK Limited
Group Regulatory Relations
Hallmark Cards PLC
Haymarket Media Group Ltd
HSBC Bank PLC
IPC Media Ltd (NME)
Jamie Oliver Enterprises Limited
Jet2.com Limited
John Lewis PC
Lloyds TSB Bank PLC
Merthyr Tydfil County Borough Council
Met Office
Microcourt Limited
Microsoft Limited
Mind Candy Limited
Moneysupermarket.com
MyMaths Limited
National Assembly for Wales
National Lottery
National Westminster Bank PLC
Network Rail Limited
Next Group PLC
NHS
NHS Choices
Northern Ireland Assembly
Public Service Ombudsman Wales
Qype Limited
Rightmove Group Limited
Royal Society For The Protection of Birds
Sainsburys Supermarket Limited
Scottish Government
Scottish Parliament
Scottish Public Services Ombudsman
Tesco Stores Limited
tfl.gov.uk
The Cabinet Office
The National Trust For Places of Historic Interest or Natural Beauty
The Office Of The Ombudsman For NI
Trader Publishing Ltd
TSL Education Limited
Turner Broadcasting System Europe Ltd
Virgin Media Limited
Weightwatchers
Welsh Government
William Hill (Bookmakers) Ltd
Yahoo UK Limited
Note - despite concerns to the contrary, the list and form of letter are both public. They were linked to from this ICO webpage.
For more info, see my summary of the EU cookie law.