You hadn't just filled up with petrol had you? If you brim it, it causes an air lock, and the symptons you have suggested. It may be worth opening the fuel cap anyway. Just remove the centre plug, and close the outer cap, and see if it will start and run.
I had your symptons after the car had been standing in the sun for a few hours, even though I hadn't filled up, removing the inner fuel cap got it running again, and it was fine after that.
BTW, the cam belt is easy to check, just take out the bolts from the front cover with a hex key and you will see if there is a problem right away.
Best of luck, I hope it isn't anything serious. Let us know what you find for the collective knowledge bank.
