I just ordered one a couple days ago from I HAVE A NOTION.com. It should be here Monday.

They can be very helpful for some and not so much for others... I think it depends on what causes your back problems :D:D:D

My nephew uses one but it is for his attention deficit. It seems to keep him more focused when he has to do homework. Sorry, don't know where to get them though.

A gal at work uses one of the large exercise balls instead of a chair. She says it helps her back, her posture and her core balance.

I was just looking at one of these in the current Clotilde catalog. Thinking of getting one for my sewing chair.

This is where I saw it also.

I have a one of those large exercise balls as well. I use it when I'm sitting at the computer. I like to try to balance on it. It's great for low back pain.

I got one at a reasonable price at a yard sale and while I don't always use it I do like it, OTOH I think I paid about $10 for it so I figured I didn't have much to lose ;-) .

It's 2 sided and if the nubs bother you you can flip it over which I have also done.

I ordered it through I Have A Notion. I was thinking of the ball but there is so much stuff in my computer/sewing room now it would not fit anywhere.

Thanks to all who have replied, it really helped me make up my mind when I read that others have used it successfully.

If you do a search here you will find lots of discussions about this cushion. Some have bought a similar one from sporting goods stores for a much better price. It is mentioned in this thread:
http://www.quiltingboard.com/t-100867-1.htm

I bought one a few years ago at one of our local quilt shows. I love mine. It helps with my posture when I'm sewing. I actually miss it when I'm not using it.