Saving a number of classes' categories

Hello,

  I've started to take a look at Squeak and now that I'm trying an
AbstractFactory, I've made a series of classes categories, mushc like
so:

Car
CarParts
CarAssembler
CarPartFactory

Each of these categories contains one or more classes.

Now, I would like to save all these related categories in one
file/package so that I know I can retrieve easily the whole kit later
without having to make 4 fileIns (or more if more categories are added).

Is there a way to do this ?

Cheers,
Al