I use Outlook for the address book (and the calendar to a lesser extent), for the reason that pretty much every application can import from/export to Outlook. N

I use Outlook for the address book (and the calendar to a lesser extent), for the reason that pretty much every application can import from/export to Outlook. No other PIM comes remotely close. It's the only reasonable way to keep my phone, my PDA, my website, etc in sync.