Room Keys

I usually stay in smaller hotels where it is customary to leave the keys at the front desk when leaving the hotel for the day.

I have a trip to Japan where I'm booked at a larger western style hotel with room cards instead of keys. Do I still leave the card with the front desk when I leave?

nope, hotel key cards are meant to be taken with you when you leave the hotel. I suppose you could check it in at the front desk if you are prone to lose things though.

Thanks YellowSmurf. Lived in and traveled to Japan for about 15 years and this is the first time I'm staying in a Western Hotel there, and wasn't too sure what to expect.

My rule of thumb is that if the key (be it a card or not) comes with the room number written on it, then I leave it with the hotel reception when I go out. If it's an anonymous-looking re-writable card, meaning noone can tell my room number should I lose it outside the hotel and someone picks it up, then I take it with me.