I do have a portable infra-red sauna thing which i go through phases of using.
I got it around nov 06 before i started doing Iodine therapy and then it would take around 20-25 mins to start sweating. Its true what they say about Iodine being needed for sweat, since being on Iodine when i go in I start to sweat in around 5 mins.
As i dont have space for a rebounder for now, am thinking of getting one of these stepper things.