I'm using OS X Lion on a MacBook Pro. I know I can use iTunes to sync music, apps, contacts, calendars, and such with iOS devices. What are my options for syncing a Windows Phone device?
Just use Windows Phone 7 Connector for Mac to sync your Windows Phone data with your Mac machine.
Windows Phone 7 Connector for Mac is a simple, easy-to-use program for Macs that you can use to:
Sync music, movies, TV shows, and podcasts from your existing Apple iTunes library to your Windows Phone or Zune HD
Sync pictures and videos from your existing Apple iPhoto library to your Windows Phone or Zune HD
Retrieve pictures and videos taken on your Windows Phone and automatically import them into your existing iPhoto library
Browse and preview media items stored on your Windows Phone or Zune HD
Download and install operating system updates for your Windows Phone
Requires a Mac computer running Mac OS X version 10.6.6 or later
To sync contacts and calendars you may use some service like Google Mail/Calendar.
I don't know any "offline" sync option to sync directly.
Mac OS X (since 10.7) provides you the ability to sync your local calendar with Google or Yahoo!.
Another option would be using an Exchange server (your own or a hosted one).