A parts bin is used in Squeak to hold several morphs. You can open it and drag some morphs on the Squeak desktop.
Takashi Yamamiya san announced an enhanced version today called "super parts bin". This one allows you to share morphs between different images through a local hard disc, a SuperSwiki server (or any regulare FTP server). By making tile scripts with a morph, it is easy to publish morphic animation in the internet.
So open up your Squeak and download the package from SqueakMap. Note that you can add your own server to share morphs. You can read more about Super Parts Bin on the "Squeak everyday" blog or test the provided japanese squeak image.