I know the importance of a good exercise routine in any weight loss plan. Right now I try to do 30 or 35 minutes on the recumbent bike at the gym at least 4 days a week, but lately it's gotten a little boring. Plus I'm not sure if the gym at my college has recumbent bikes, so I'm wondering about other options.

My main limiting factor in mixing things up is that I have weak knee joints (always have), so activities like jogging, doing lunges, and even just walking up a lot of stairs can cause my knees to pop/crack audibly and be very painful. So I'm wondering about some other good fat burning/cardio workouts or gym equipment that won't put a lot of stress on my knees... any ideas?

I really really want to buy a wii fit for nintendo as they seem to provide low-impact not so strenuous exercises that can be done at home, inyou own time - who has one - it is worth all that money!?