Buying a phone with WP7?

You don't have to upload your address book to Windows Live, you can sync it with a Google account if that's easier (it was for me)

I had an ancient Hotmail account I used for signup, but now barely ever check it. All my contacts came via Google and my iCal is synced with Google calendar.

No. 1 thing to do though is make sure any account you do sync with is tidy BEFORE you sync. It's a lot easier to bin 100s of dead contacts from a web interface than delete them from a phone! :)
 
You don't have to upload your address book to Windows Live, you can sync it with a Google account if that's easier (it was for me)
The problem is that Google adds to my contacts every.single.person I write an email to.
Say I write an email to a company: it gets added to my address book. It's really annoying actually...
That's why I'm not syncing my address book with any service!