Just seen a message from Calumet and among the various offers, they have a buy-one-get-one-free [B-O-G-O-F] promotion on their umbrella swivel adapters. These adapters go on the end of a light stand and let you use your camera flashes to fire in to or through an umbrella. I have a couple of the similar Manfrotto 026 umbrella adaptors
So if you want one, and can find another club member that also wants one then that makes them a tenner each.