Alfred Molon wrote:
[...]

If you need to make a lot of phone calls back to the UK, the best is if
you use Skype (bring a netbook or another cheap and light notebook with
you).

And how would that help?

You still need an Internet connection. That Internet connection is
either non-mobile (i.e. Internet-cafe, wireless hotspot, etc.) or mobile
(i.e. via a mobile phone/modem). If non-mobile, then you might as well
use a normal (non-mobile) phone and a pre-paid calling card. If mobile,
the charges (per MB) will still be rather to very high.

A callback scheme may be cheaper. I.e. you call your provider, your
provider sees it's you, disconnects and calls you, so there is no
outgoing mobile charge. Next you 'tell' your provider to connect you to
number X, so you only pay what your provider charges. I have no
pointers/URLs for this, but if you Google this group, you should be able
to find some.

Yet another alternative is comfi's SMS-Call or WEB-Call. I haven't
used either, but have looked in detail at their SMS-Call, and it looks
very nice. For details, see http://www.turbocall.com.