Manfrotto 244N Magic Arm

I got this along with a super clamp. I use it for mounting small flashguns. I attach an umbrella holder on the end which isn't in the super clamp. Its rated for 15kgs, and while I have't tested it with that much weight, I'd be happy to put any kind of flash on it. Once its tightened it really is very solid feeling.
When you release the wheel, the whole thing goes limp, including the ball joints at each end, so you can just hold the flash, loosen it off, reposition then retighten.
You can also get a camera mount to mount an slr or other camera for remote operation.

One of those things you shouldn't save money on. I bought many variations of these in the past from different brands, but regret not buying the Manfrotto's straight away. Save yourself some money, and buy the real deal!