I'm seriously considering an indoor play centre for Sam (and the other kids too, of course, but mostly for Sam). My high energy, agile, super fast, wrestling, want to be a stuntman 4 year old. I just stumbled across this company, Dream Gym, that actually sells indoor jungle gyms for small spaces. And the best part...they are located in Ontario and ship to Canada...and it's free shipping if you spend more than $75!
OK, the above structure might not fit in Sam's room, but at the very least, I would like to get some rings and maybe a ladder, or how about this: