The Icelandic Krona

The króna (plural krónur) (sign: kr; code: ISK) is the currency of Iceland. The króna was historically subdivided into 100 aurar but this subdivision is no longer used.
The word króna, meaning "crown", is related to those of other Nordic currencies (such as the Danish krone, Swedish krona and Norwegian krone) and to the Latin word corona ("crown"). The name "Icelandic crown" is sometimes used, for example in the financial markets. 
Iceland is not currently a member of the European Union and does not use the euro. The Icelandic currency is a low-volume world currency, strongly managed by its central bank. Its value in terms of other currencies has historically been volatile, for example against the US and Canadian dollars, and the other Nordic currencies (Swedish krona, Norwegian krone, Danish krone, and euro). For example, during the first half of 2006, the Icelandic króna ranged between 50 and 80 per US$. Prior to the currency's collapse in October 2008, the króna was considered overvalued.
At most shops electronic payment is accepted. Other currencies are very rarely accepted in Iceland. 
A notable exception is Keflavík International Airport (which has many transfer passengers), where the US dollar, euro and some other currencies are accepted by all merchants. Certain stores in downtown Reykjavík accept some foreign currencies.
Iceland's overall level of technological sophistication is noteworthy. Iceland's per capita computer usage, for example, is among the highest in the world: far higher than the UK or US. The saturation of technology in Iceland has had ramifications in the monetary system: a very high proportion of payments in Iceland are made electronically, e.g. by debit or credit cards or online bank transfers. 
The largest denomination banknote, the 5000 krónur note (around €30 in April 2012) has a relatively low value. Iceland may move further towards a semi-cashless economy.