I received information about this site today and have taken a closer look at the destinations list. There do appear to be some very reasonable rates for certain destinations, notably:
Australia Mobiles - 1 unit a minute (for operators: Hutchison, Optus and Globalstar)
Aruba Mobile - 1 unit a minute
Belgium Mobile - 2 units a minute (for operators: Base, Mobistar and Proximus)
Brazil Mobile - 2 units a minute
Bulgaria Mobile - 2 units a minute
Colombia Mobile - 2 units a minute
Congo Mobile - 2 units a minute
French Guiana Mobile - 2 units a minute
Hungary Mobile - 1 unit a minute
India Mobile - 1 or 2 units a minute, depending on which network
*North Korea - 1 unit a minute
Portugal Mobile - 2 units a minute
*Qatar Landline and Mobile - 1 unit a minute
Reunion Mobile - 1 unit a minute
Romania Mobile - 1 unit a minute
South Africa Mobile - 2 units a minute
The site also lists UK 0844 numbers at 13 units a minute and UK 0871 numbers at 7 units a minute. I would think that some of the rates quoted may be typos, especially for N. Korea and Qatar. Test reports on this service would be most welcome.TIA.