Omaha has a Multiple Sclerosis gym here. It's run by a guy who has MS and he's hired a bunch of physical therapy people to help the MSers with their exercises. (they also have people with other medical conditions that go there too)

It's apparently fairly inexpensive, you dont have to sign up for a contract and it's gotten a lot of good reviews.

However, I havent gone yet...the whole River Denial thing. But, I am starting to consider it. If anything, I might manage to lose a few pounds going there.