My friend just got a great storage ottoman from Value City Furniture...I am planning to go out and get one myself. She and I both have little ones just learning to walk, and this ottoman is well padded and attractive. My friend uses hers as a substitute for her coffee table, so it might be a bit larger than you were looking for, however they may have a smaller option available. I have also seen these in the past at Bed Bath & Beyond, they may not be too expensive if you have one of the coupons they frequently put in the Sunday paper.
I have also seen crafting ideas for creating your own ottoman if you are crafty, you might try searching the internet for something like that (if I remember right the one I saw in a magazine used a milk crate) Good luck!!
