After struggling with that I am now using soonr.com (free).
After 5 minutes I had it setup on my PC and could access all my Office docs and PDFs on my iPhone. Very cool.
It also allows me to view Office docs that are on my PC as PDFs on the iPhone. Can also email myself any file I want, and then view the email on my iPhone.
Can access Outlook email, contacts, and calendar entries too, but since I already have that data on my iPhone I'm not so sure how useful that will be. Though I can see emails, for example, that aren't on my iPhone (sent items, etc.).
Anyway, this seems to be an OK solution till real on-device storage is addressed (though I will likely continue to use SoonR if it's free).