Have you considered yoga? I bet you have. Get a DVD and do it in the comfort of your own home. I am gravitating toward it as a great way to stay flexible as I enter the realm of getting old and stiff (and grumpy) ;).

Low impact, go at your own pace moves which really seems to help prepare my body for other types of activities. Plus it builds some strength. Check it out.........I don't know about you but I'm getting ready for next years trip now  :).