Apple's MobileMe News has posted a helpful entry on using MobileMe's iDisk for easier file transfer for the just-updated iWork apps for iPad.
With the latest Keynote, Pages and Numbers for iPad, you can now transfer your documents directly to and from your MobileMe iDisk so you can work on them anywhere you have an Internet connection. For example, create a new Pages document on your iPad and copy it directly to your iDisk. Then, when you are back at your Mac, open the document from iDisk and continue editing right where you left off.
If you're working from a Windows PC, access your iDisk with a browser at me.com/idisk and upload an existing Microsoft Office document. Copy the document into Keynote, Pages or Numbers on your iPad to view it or make edits. When you've finished working on the document, copy it back to your iDisk as either an iWork, Microsoft Office or PDF file.
It will also work with WebDAV. Would that it would work with Box.net, DropBox, and GoogleDocs...