I assume you are talking about Exchange Public Folders because there
is no such thing like Outlook Public Folders. What kind of data does
the Exchange Public Folder in question hold?

Yes, Exchange Public Folders. They contain Mail and Post items.

Assuming we are talking about Exchange 2000 or 2003, there are several
options.

1. Create a SharePoint document library and map a drive to it. Then
either use Outlook Express (with IMAP configured) or Outlook
2000/2002/2003 (with the Exchange MAPI provider) to access the PF and
drag & drop the items into the SharePoint document library.
2. You can also automate this process with a simple Windows Scripting
Host script which maps the drive(s) and copies the data.

Anything beyond needs advanced programing skills as per documentation
in the Exchange SDK and the SharePoint SDK.