Adding 'panels' to repository

Can I add something to the Object Repository that is not a complete
form?  I would like to create some panels with edit fields, buttons,
etc., and then be able to use one or more of these panels when
creating a new form.  (For example, I could create an Address panel, a
Transactions panel, etc., and then if I wanted to have a form that
showed someone's address and their transactions, I would combine the
Address and Transactions panels onto one form.)

I know I can add forms to the repository, but if I add each panel as a
form, how will I be able to combine two of them to make a new form?

Thanks for any help.

"Emergency!  Everything is uncool.  Send the mothership."