Nakahara Informatics has released
iGet Mobile, remote access software that lets you access files on your Mac from an iPhone or an iPod touch. It costs $39 (but is available for a limited time for $29).
iGet Mobile is software you install on your Mac. In addition to the iPhone and iPod touch, it also works with Windows-equipped PCSs and other non-Mac devices. It provides a lightweight Web interface to the files on your Mac, but has special features designed for iPhone users — such as on-the-fly document conversion, so you can view a large Photoshop document to a format more easily viewed on a mobile device, or an RTFD document can be rendered as a PDF.
A downloadable demo is available. iGet Mobile requires Mac OS X v10.5 or later.