To the original poster...
before you do anything, make sure you forst sync with eithe MyPhone:
http://myphone.microsoft.com
or activesync or Windows Mobile Device Center (depending on your version of Windows).
That way you won't lose your contacts, calendar, tasks, documents, pictures, videos, and other personal data in the event you hard reset.
In MyPhone just set it to sync everything, but uncheck the storage card (since a hard reset doesn't erase the storage card anyway, and you probably don't have enough space to back it up online either). Then you can log in from the website and archive/delete whatever you don't want.
This is a must though. If you lose all your stuff in a hard reset and you don't have it backed up it will be gone forever. I don't know about you, but for me that would be devastating.
MyPhone is the one I suggest. And I am attaching a cab to this post in case you don't have it yet. You need a hotmail/live/msn email address to sign in with, so if you don't have one yet go to hotmail.com and get a free account. Then just install this cab on your phone and sync it. If you already have one just install this cab and sync.
After you hard reset, install the cab again and sync again and it will bring all your stuff back.