When I first began the game, one of the features that I thought was particularly fun was picking up random objects and throwing them at enemies. It was useful for controlled pulling for characters who didn't have ranged attacks, and could do a surprising amount of damage.
Eventually, however, this tactic (as well as bashing people over the head with them) becomes obsolete, as improvised weapons tend to be rare outside of Millenium City, do too little damage at higher levels, and break far too easily.
It would be nice to see improvised weapons improved somewhat, and if it isn't too difficult, for a few more to be added to zones which don't have many. Perhaps there could even be some objects that are especially durable in zones that don't have a lot of objects (perhaps even able to be thrown more than once).
Full disclosure: I do have a character that canonically likes improvised weapons, so my intentions here are slightly selfish. Nevertheless, though, I think it would make the game a bit more fun for a lot of people, and I don't see it creating any significant problems, as they still wouldn't fit into any content that is particularly difficult (what are you going to do, throw a boulder at Qwyjibo, then go over and pick it up again, all without ever needing to block?).