My 7 month old LOVES his stacking rings. He also has a ball made by v-tech - I think it's called The Crawl Ball. It rolls on it's own to give the baby an impetus to crawl after it.
My baby will be 8-9 months at Chanukah. I'm getting him the Fisher Price Crawl and Cruise Musical Jungle (it's $49.99 at Target right now with a coupon) and the PlaySkool Busy Ball Popper. I have an Intellicube and I'll probably get more intelliblocks for it. There are also the Fisher Price Rollaround balls. Those rock. Oh! And the crib toy - the one that's remained unchanged for like 50 years - ties to the crib and gives the kid something to do when he's bored in the crib. I can't remember, but I think it's a Fisher Price toy and it's called the Crib Activity Center or something like that.
I'm really a huge fan of Fisher Price, in spite of their recalls last year.
at 8:32 PM on Nov. 6, 2008