My cats LOVE bags, especially when someone visits, family or my boyfriend, as soon as they place their bag down, my cat(s), have already noticed and are approaching it, as for plastic bags, they go absolutely nuts. Also my oldest cat, has a thing for laundry baskets, you can always catch him sleeping in them.
Well, cats DO love hiding, and they love exploring. Most cats I know or have known love bags, too! Just make sure you don't let him have plastic ones. Paper ones are great and make great sounds when he's in them. Plastic ones can be harmful, though, as they can be to kids or anyone else. Paper bags or your purse or briefcase? Pure fun!