Hmm. I'm not sure, but things that come to mind are weight sets (small & large) from argos or similar, excercise ball (argos, boots, those bad boys are all over the place), a small trampoline (fun...and bouncy! and fun!), some really good trainers (walk, run, limp!), or a bicycle. Or some combination of all of those things.
Good luck with your exercising!