This is my favorite app to date - "FileMagnet makes it easy to copy files from your Mac and view them on your iPhone and iPod touch. It supports all the common file types, including PDFs, Microsoft Office documents, images, movies, sounds and even folders. By running the FileMagnet Uploader on your Mac, you can wirelessly copy files over your wi-fi network." - Steve Rubel from Bookmarklet

unfortunately not iwork docs though.... :( - Zee.

Like this one a lot too - wish it was two-way though, able to send files from iPhone to Mac ... - Patrick Jordan

I've been using sugarsync and that works remarkably well - Zee.