And I just thought of another one that I currently have in my cage: Bougainvillea.
In the right conditions, they will keep their leaves year-round (although where I live they tend to drop leaves at the first sign of frost in winter). And they generally flower quite abundantly.
The other benefit of Bougainvillea is that they grow strong, woody branches. If you get a variety that creeps, it can grow fast, and provide quite a nice climbing structure for your cham.
I'm not quite sure about the long-term practicality of Bougainvillea though. Although they're also included on the 'safe' lists for reptiles, I'm not so sure whether they'll thrive in a cage. They prefer to have soil that's more on the dry side, and I think the light might not be strong enough to get them to flower.
Having said that though, my plant has just sprouted a whole bunch of new leaves after being in the cage for a month, and it actually seems to be growing quite well.
It'll take a few more months before I can be sure though.
Hoya is a non toxic succulent type vine that produces umbels of star shaped flowers. It makes for a good enclosure plant because of it's resilience to being climbed regularly. The vines will also root onto things, kind of like pothos. It prefers partial to full shade, so I usually use it as an understory plant. I find it grows the quickest in a half sphagnum/sand mixture (does not like heavy soil).
Thanks for the Hoya tip Sean. That might be just what I am looking for to fill up the rest of my cage. I wanted to use Trumpet Vine (which grows abundantly in our area, and has really attractive flowers), but it has come up on a few of the toxic lists that I've looked at, so I decided against it.
Hoya might be the solution, and a good alternative to Pothos. I'm not a fan of Pothos at all, simply because they use it as a pot-plant in all our offices here, and so it just ends up reminding me of work...