I'm building myself a reflective chromakey solution. It's usually called 'Chromatte' and obscenely expensive, but produces superiour results without any lighting needed on the screen itself (except for an LED lightsource) and no problems with spill.
They're perfect for small rooms as as your talent can stand close to it without spill, you get very even colour, and you can even change the material between a green and bluescreens at the flick of a switch!
If you're not familiar with them, the idea is that the fabric is highly reflective (like street signs), and because it is, you can light it up with a very low-powered LED lightsource (a ring of LEDs around your lens). The light is so low that it won't be picked up on your subjects, but brightly lights the reflective screen from the camera's point of view. And as the LEDs supply the colour (the screen looks silver in normal lighting), you can simply switch between blue or green LEDs to change between blue and greenscreen instantly.
Here's a video:
I have found a source for the fabric for myself, and have ordered some LEDs to make the ring with. They are already tightly connected together in a strip, so all you need to do is cut them to size and add a 12V DC supply. I will also look at wiring a small control box that allows dimming (to get the right exposure) and switching between blue and green LEDs.
If there's any interest I might be able to get more of the fabric, and maybe even make a few LED rigs. What screen sizes would you be interested in, and what would you be prepared to pay? (remember this is pro stuff and not cheap).