from last year here). The ITU has issued the 2012 version of its annual report, Measuring the Information Society. This report is probably the single most authoritative and comprehensive study aimed at measuring ICT for development, as it is conducted by the ITU on behalf of and with input from all of its member states.
Again this year Korea ranked number one in the world on the ICT Development Index (IDI) aa composite index that combines 11 indicators into a single benchmark measure used to monitor and compare developments in ICT across countries. These indicators are grouped into three sub-indexes corresponding to ICT access, ICT use and ICT skills.
I've reproduced one of the charts from this year's report at the upper left (click on the graphic to see a full size version). It compares the global distribution of gross national income for selected countries in the world, on the left, with subscribed capacity (a measure of the capacity of fixed, mobile, voice and data telecommunications subscriptions). In essence, it shows that Korea has huge capacity, relative to its GNI, as shown by the difference in size of the red slices of the pie chart. Another way of thinking about this is speed. South Korea has far and away the fastest digital networks in the world.