Can the owner trace his iPhone 3GS 16Gb?

I found a iPhone lost today.. I looked around to see if anyone forgot it there, but there was no one near me, or looking so I grabbed it (I didn't steal anything). I removed the SIM card. Now I'm wondering if the owner can find the iPhone using some app or I don't know... I already reset it and erased all of his things... Is there any chance of him finding me? Thanks!