On the contrary, it is your mobile sync software which is "of no use if communication with the outside world is required", if it doesn't support standards-conformant mail clients like Thunderbird, but only communicates in non-standardised ways with the products of a single company.
Note that some PDAs come bundled with a synchronization software for PC that supports only Outlook (not even Outlook Express), and with a CDROM and licence to install Outlook (Toshiba PDAs for example, running on Windows CE).
The synchronization uses Microsoft ActiveSync, which uses its native support for Outlook local folders only (does not work if you have something else than a standard POP3 account configured or a private Exchance account, because it won't synchronize other types of Outlook folders like HTTP on MSN or Hotmail... despite it's also a Microsoft product).
And there's nothing for Mac users.
Well you're free to buy other PDAs, or to buy and install other synchronization software for your PDA. Synchronization still lacks good standards, like instant messaging and chat, or management of personnal calendars or contact lists...
May be there's something in Sun's Open-Office that can connect you to Windows CE PDAs or other types of PDAs?
