Since I have two dogs that go almost everywhere with me, I normally don't carry a purse (need both hands) but carry a small nylon billfold in my pocket with a car door key inside. However, I've got myself in the habit of always using the remote to lock and unlock doors and haven't locked my keys inside the car in years. I live in a semi-rural area on acreage so I do have a hiding place for a house key, that's not too close to the house and doubtfully would be found by anyone else.