Went round my mates tonight to sort his pc out, and he got this ball thing, wound it up and started twisting his hand.
He passed it to me, and it was quite mad, took some getting used to, and my forearms were aching and swollen after. Thought Ive gotta get one of these!
A trip to Argos and £7.99 later, I have one. They are AWESOME for forearm training and also good fun and relaxing also!
Need to get a new battery for it tho so I can see what RPM I get it up to!
Heres a link:
here