This is a great idea.... I spent a couple of days looking at chair cushions online last weekend. I settled on a large firm wheelchair cushion with 1/2 memory foam and 1/2 regular firm foam...from Overstock.com It came yesterday, and it is divine!
It was only $27.00!

Why didn't I think of this? I want to thank you for the idea. Much less expensive than getting a new chair, --my old computer chair I think has been making the backs of my legs ache.

Mrs. D,
You are most welcome! I work in a residential facility where many people are in wheelchairs, so I was able to consult with one of the PT's to get recommendations for what might help with my "sitting". I continue to be very happy with my cushions. As I mentioned in another post, I recently took my cushion to a 2 day conference. So as not to feel odd walking into the conference carrying my cushion, I carried it in a large tote bag. Without my cushion, I probably would have done a lot of standing during the lectures. I hope you continue to enjoy your new cushion. Happy sitting!