Apparently when you phone the NHS people and they ask you your symptoms there are 2 symptoms that people with just regular flu don't get that Swine Flu people get! (Maybe oinking and getting sunburnt easily!)
But there you go - they will then know if you have proper swine flu or just a bad cold or normal flu!
Disclaimer - this came from an associate of DH who he calls Fat Wanky Paul - so can't be sure just how accurate it is!