SamD
I needed people in Australia to be able to contact me on my work number which was permanently diverted to my mobile. So I bought a Skype number which is about $9 /mth as well as a basic subscription for $5 which gives me 300mins worth of calls to Australian landlines and mobiles (1800 calls are free). I diverted my work number to my Skype number and so far it has worked perfectly. Of course it only works when I am online but in Bali that is most of the time anyway.
Goodbye highway robbery roaming charges forever.
Maybe everybody else in the world has worked this out already anyway but there may be some pygmies in equatorial Africa who are unaware of this trick.