Now that my son understand the word "Shake", he loves this toy so much more. He will crawl across the room for it when he see it. It amazes me what kids will turn into their favorite toy. We can spell loads and loads of $$ on toys we think they will love, but most of the time my son goes for the simple and free.
Empty vitamin/medicine bottle
Rice, beans, or corn
* For safety issues you may ALSO want to tape the bottle closed to ensure a tight seal. Make sure the container you choose is indeed child proof.