OK, I have both!! Lightweight Tripods seem to come in two varieties, compact or tall. compact ones fold down into something much shorter, but don't always go as tall. When a lightweight tripod is tall it isn't necessarily stable and strong winds can cause vibration. I have a lightweight Giottos (CF - around 1kg) but that is not very compact when folded, and a lightweight 3LG Punks, which is very compact when folded (32cms long, 1.5kg)), but doesn't go as tall, it is though much more stable than the Giottos. I also have a couple of gorillarpods, I find these very useful, often attaching to railings or even using as a low level tripod. If you have a lightish camera/lens, then if you go for a gorillapod, I would recommend getting one with some adjustment in the head, as when using them on railings and the like, they can be difficult to level the camera.
It really depends on the type of holiday, a gorillapod is certainly easier to carry, and never seems to fall foul of any tripod police.