Originally posted by naisme
And a final option that I've seen used by some is to just get a regular bottle cage and use those clamps that have a screw to tighten, like you use on water tubes in your car, to hold the cage on the bike tubes.
Or if you don't fancy the hose clips you can use zip ties. I've done this in the past, with cut up bits of old inner tube around the frame to protect the paint.