The iPhone syncs contacts, calendar entries and even browser bookmarks with a PC or Mac via iTunes, but can you also sync the notes you take on the iPhone with your computer?  The short answer is no, at least not with iTunes as it is currently designed.

There are some workaround solutions, however.

One such solution allows you to copy notes from Outlook (on a PC) to the iPhone, but the process involves scripts, databases and the like.  If you're up to it, you can read more about the solution here.

EverNote

The most elegant note syncing solution we've found is provided by a service called EverNote. Although it does not sync with Outlook or Entourage, it does provide a syncing solution with its own desktop software and the EverNote web site. 

Just download the Evernote iPhone software, the Evernote Desktop Client, create an account and you're ready to go. 

Notes created on the web, the iPhone or your computer are available across all devices, and changes made from one location are synced with the others.