http://address.yahoo.com/?A=x&A2=11
Yahoo has free Intellisync software that will allow you to sync contacts, calendar, notes. In the past, it would allow syncing only to Microsoft Outlook, but it looks like they've updated and can sync directly to PPC. I found that it goofed some of my fields (spouse and children fields in PPC readily come to mind), but none of the important stuff. There was also a problem with categories, I think, but I don't remember.
I now have mine set up to not sync Outlook and Yahoo, but to push all data to Yahoo, which is another option. I only use Yahoo as a backup for what is getting to be the rare occasion that I don't have my handheld. I can look up any numbers I need on my mobile phone using Yahoo's wap site. Also saves tons of time adding numbers to the mobile phone address book, because I can access all this info. online.