I knew this would come up soon. I don't have any glass, but I have been thinking about ways to do this. I don't think there is any practical GonG solution, but something like the new Magic-Flight Water Pipe Whip would work easily. You have to shrink wrap the end of the tube inserted into the FV to make a good connection, but that's a trivial issue. The issues I see with GonG (disclosure: I know little about glass) are the small (I think ~7mm) outlet, the placement of the outlet on the side of the FV, and the fact that you have to keep the FV more or less vertical while in use.