You might think the title is ironic, but indeed, it's not. While Microsoft's own Windows Phone 7 features tight Office integration and excellent support for Word, Excel and PowerPoint files, most of that integration revolves around the cloud: for business users, that's SharePoint, for consumers SkyDrive. That does work nicely, but sometimes, the easiest way is to transfer files straight from your desktop PC or laptop to your phone.
Since the Zune software, which synchronizes music, pictures and videos, does not do the same for Office files, the only way to accomplish that is with a homebrew tool called Office File Uploader.
It's pretty easy and straightforward to use, provided your Windows Phone is developer unlocked. Just run the EXE on your desktop, connect your device (make sure it's also connected via Zune) and click the upload icon to select the files you want to have on your Windows Phone. That's it – now exit the Office Hub using the back button to let it refresh, and the files will appear in there.
The same even works for PDF files, just switch to the PDF tab (see screenshot). However, you'll have to use a modded version of Adobe Reader, instead of the one available on the Marketplace.
Sounds good? Find the download links at xda-developers.