Here is a piece of camera gear that Cool Tools posted about. It is touted as a more portable alternative to using a monopod.
Pocket-size stabilizer: Strap Pod
In the case of museums or some public spaces, tripods are simply not allowed (though you can sometimes get away with a monopod by pretending it is a 'walking stick'). But again, hauling a monopod around is sometimes clumsy, frowned upon, or outright discouraged in certain environs. The Strap Pod is much less intrusive and bulky, so I'm more likely to toss it into my pocket or my camera bag and bring it along.