This international SIM from O2 might be up your street if you phone abroad a lot, with calls to international landlines and mobiles starting at 1 per minute.
Check out O2’s international SIM page and select a country to see the landline and mobile tariffs. I’m a bit gutted to see Wallis & Futuna at the higher end of the spectrum.
Top up with £10-14 for unlimited texts to O2 numbers, or £15 for unlimited texts and calls to O2 peeps.
(Thanks to NRE123 at HUKD)