Steve pointed this out in another thread, but I'd not seen it before so
worth mentioning:
http://www.vectonemobile.co.uk/
is a new PAYG - someone mentioned it's a T-mobile virtual. Some of the
promotions are interesting, though they all expire at the end of December:
1p/min on weekends to quite a few countries. The number of minutes is
restricted, but some of the countries are in traditionally 'expensive'
territory (eg 20 mins to Afghanistan, 1000 to China). There's a catch in
that this only works the weekend after you've topped up (so it's not quite
such a good deal as it originally sounds). Minimum topup is 5 pounds.
5p/min to UK mobiles and landlines, and 5p/text
Free Vectone-Vectone calls for the first 10 mins, then 5p/min.
Apart from the promotions, which are rather headline-grabbing but not
terribly useful afterwards, the prices on non-weekend international calls
are good - better than Lycamobile for the countries I checked.
Now I strongly suspect prices are going to go up in January, but if you can
use a topup's worth before then it's got quite a few things going for it.
Theo