The Tobin Tax
http://www.parliament.uk/business/publications/research/briefing-papers/SN01346
Discusses the origin and controversy about the Tobin Tax, proposed by American economist James Tobin in the 1970s to discourage currency speculation. The recent financial crisis has caused policy makers to look again at the idea of taxing financial transactions as insurance against excessive, risky speculation by large financial organizations. From the House of Commons Library