Ugh! I woke up this evening to find two splats of kitty vomit on the floor! In the 2 years I've had cats, I've discovered regurgitated messes only some 3 or 4 times, and, thankfully, it's always been on the tile floor and never on carpet or furniture!
I don't think it's hairball-related - that's never been a problem ... even more so now that I recently bought a FURminator!