Phoning the UK from Fiji

any suggestions on the cheapest way to phone home to the UK from Fiji? should I buy a sim card for my phone or use the payphones?.....
thanks!

I would actually go into an internet cafe in Fiji and call on skype since their rates are very low and u could also talk via webcam or online with ur family members if they are on skype. Purchasing a sim card for your phone won't give u as much time!!