Public sector ICT will be revolutionised by cloud computing. Public Sector lawyers will increasingly be asked to advise on cloud computing raises. This paper provides an overview. More detail on public sector procurement is in our related article, Public Sector procurement and cloud computing.There are two other related articles: (a) Cloud Computing: the reality; government procurement; and regulation/anti-trust: Address at Communicasia Singapore and (b) Cloud Computing: Regulatory/Anti-trust risks and solutions.