Tripods are great, but if you have had to lug one around for any length of time, you know what a hassle they can be. There are some pitfalls, however. In many places, you cannot use a tripod at all, as it classifies you as a commercial shooter; some places won’t even let you enter if you are carrying a tripod.
The workaround? A monopod.
There are a number of good ones on the market, and a few have the ability to collapse for easy packing, and be used as a walking stick until you need it for a shot. Obviosuly, you can’t do a self-portrait with a monopod, but it can give you a much more stable shot when you are behind the camera. Also, you can always claim it is for walking (it is!), therefore you should have no issues with access to museums or sites.
To summarize: you get most of the stability of a tripod, lighter weight, collapibility and ease of packing. I highly recommend you check out a few and if you find a good monopod, chime in here with a comment.