I love gadgets, but nothing has got me hooked like the iPhone has, since MacWorld 2007.
I've had Walkmans, Gameboys, Discmans, iPods, still have a PSP, other mobiles before iPhone, etc, and all of these had had me under it's spell for no more then a few months, before I eventually get bored and they then become irrelavant in my world.
But not this thing. I've had my current 3G for just under a year, before that, a first-gen iPhone since February 2008, and before that, a first-gen iPod touch since November '07.
Nearly two years on since my first introduction to the iPhone OS(not including obsessing over the iPhone blogosphere for months, before it's launch in the UK), I'm still in love with this thing, and it shows no sign of abating.
Rival mobiles since have made me go "oohh and "wow", but always only for short periods.