Oceanic makes two different versions of this cage. One is called a "chameleon lounge" and it comes in a 45 gallon size, which is ok for small to medium chams. Both sides are about 1/3 screen, the front back and top are glass, the top has a screen cutout where the light goes so that uvb gets to the animal. Whats cool abuot that cage is that the sides and back are smoked glass, but you still have to worry about the cham seeing its reflection in the glass.
They also make another tank called a Lizard Lounge E Series 90, which comes in 45 and 90 gallons. It has two screen Doors, one on either side, and the whole top is screen. The sides are probably 2/3 screen, with a small glass "lip" to keep water and or substrate in when you open the doors. I like this cage better because its taller htan the above model. Its narrower as well, so you trade off, but i do like it better.
Both of those tanks can be found for apprx. $120 from any petstore that carries oceanic fishtanks.
Creative habitats also makes many many screen/glass models, but they're all way too narrow for my taste. The biggest one ive ever seen is only about 18" wide, which, IMHO is not wide enough for most chams. It'd probably be OK for a carpet though because they dont get huge, in my undrestanding. Someone correct me if im wrong. 
Those cages are also pretty reasonable...we have one thats about 12 x 12 x 24 for $99.
Sometimes its nice to work in a petstore.
Hope that helps a bit!
Jamie
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Jamie A. Stine and the Gang:
1.1 Bearded Dragons (Lancelot & Guenivere)
1.0 Giant Frog Eyed Geckos (Peanut Butter)
0.1 Borneo Short Tailed Python (Ezmerelda)
0.1 Red Tailed Boa (Buffy)
1.0 Short Tailed O'possum (Jethro)
1.0 Greyhound (Hank)
