I am creating an Excel workbook with custom toolbars. I want to move
this workbook to different computers. How do I move the toolbars along
with the workbook and will the toolbars also work on a Mac? I have
created some macros that are assigned to the buttons on the toolbars
and wonder if these will also work on a Mac?

Les, there is a straightforward way to bundle a custom toolbar with a
workbook.  From "Chip" on the Excelforum.com discussion boards:

"While the best practice is to dynamically create toolbars with
code, you can attach a toolbar to a workbook. Go to the View
menu, choose Toolbars, then Customize. In that dialog, click the
Toolbars tab, and then Attach. In the Attach dialog, select your
custom toolbar in the left pane and then click Attach."
     [http://www.excelforum.com/showthread.php?threadid=189426&highlight=transfer+custom+toolbar]

Regarding the PC-Mac macro compatibility -- for the most part,
VBA-written macros seem to transfer reasonably to Macs from PCs, but
there have been some known problems.  If you aren't using 3rd-party
add-ins with your macros, they most likely will work, but there are
still a few "native" functions here and there that aren't supported on
a Mac.  I would recommend attaching the custom toolbars, and then
trying the macros out on a Mac -- until then, it will be hard to say
for sure whether those exact macros may have to be modified to work on
both systems.

Please let me know if you have any further questions.

--Joey

Searching strategy: 
     - Google: custom toolbars excel transfer
     - That led me to www.exceltip.com
     - There, I searched the forums for "custom toolbars transfer"