Scooters can seat two. I had an 80 last time but my friend had a 50, I think the guy gave me his own as he was sold out. There's storage under the seat as well as by your feet, some may have racks. I just lock it (and lock the helmet inside the seat) when I park places, but I only park where parking is secure.

Ive not rented a bicycle but I'd want to rent a lock if I did.