ChezBez

Hi... I'm new to Geocaching and attempted to find my first cache last weekend using my iphone but was unable to find the cache. Having read this I am wondering if it is because my iphone 3gs is not accurate enough? I can see people say they use hand held GPS... would this include the TomTom sat nav? I didnt realise satnavs could find caches as I havent seen geocaching on mine... is anyone able to enlighten me or am I being really thick regarding this technology?! Thanks, Chez .