http://www.dropbox.com/

Free (with pay option) and syncs across the board. Just save everything into the native Dropbox folder after installing the app and you're golden. Also comes with an iPhone app.

As for email and calendar, if your father is using an iPhone, you can set it up to synchronize calendars and contacts with gmail. You can also set up iCal in a similar manner and everything should be good to go.

Set up is a little more intensive with gmail but I have found that they offer vastly superior mobile access than MobileMe. Tried checking my email with MobileMe (before I canceled) on my dad's Blackberry (before I had my own iPhone) and it wasn't supported. Nor was it supported on some older browsers. Deal breaker.