vegas - Get yourself an outlook account. You can set it up w/your current gmail account (that's what I did years ago). Then, when you log in, go to People (click on the arrow that will show up when you mouse over "outlook" in the top left corner). Link up to your FB account, and notice how it pulls all those contacts in. Export your contacts from gmail and import them to people. Link accounts up where you have multiples (like you stored John Smith's cell number in gmail, but you also have them as a fb friend). Pull in your linkedin accounts and/or whatever else you have.
Now, that entire contact list that you spent so little time hooking up? Once you link your windows account to your WP, which is the first step you do... EVERY contact is instantly available. From the work you just did.. on your computer. Those contacts are also instantly available to any other app on your WP that hooks into the People API. Any changes you make to the contacts on your phone? Instantly synced up to your people.live account.
Now back to the live account. If you click up where you went to find People, you'll notice you have skydrive as well. Here, you can store all your documents. Better yet, download the skydrive app to your computer, and ANYTHING you put into the skydrive folder on your comp is instantly synced to your skydrive account online. Even better, if you allow the proper permissions on the skydrive app on your desktop, the files on your desktop computer... anywhere on your computer... are now accessible from any computer simply by logging into your skydrive account.
Finally, don't forget that you get a full suite of MS office apps on your phone... just because you have a windows phone. And yes, all those apps sync to skydrive, along with any pictures you take on your phone (and of course you can turn any/all of this off if it freaks you out to be that connected).
If that ecosystem doesn't sell you, I don't know what will.