I'm trying to remember exactly what I saw a few years ago but I thought it was one of those glider type exercise things, but it collapsed and slid under a bed or sofa. Does anyone know I was I'm talking about? I'm wondering if they are something worth looking into but I can't think of who might have made it and I haven't seen anything really fold up in the store. We have almost no extra room in our house so thats what got me thinking of those instead of a treadmill or something.