If you want a good climbing plant, nothing beats the pothos. It grows alot and fast on everything it can. It's very hardy and will support many tree frogs species easily. And it's nearly impossible to kill.

http://www.frogforum.net/members/vip...8284-front.jpg
It's the one haning in the middle of the tank planted on the right side and in the back. However, this picture is 3-4 weeks old, which is VERY noticable with this plant. It has grown alot since then

EDIT: Forgot to mention how it climbs. It uses root-like extentions which it uses to attach itself. They are somewhat "sticky", and will attach itself to anything with texture (the background, vines, rocks, tree logs etc.), so you can create really good-looking stuff. Mine for example, is now twisted along the front vine in the picture.