Box.net, providers of free and paid-for Web storage have a slick new front-end for iPhone users. Once logged into your box.net account, you can access all your files and folders, using a scrolling hierarchical interface similar to that of the iPhone and iPod. Since it's still the same old Safari browser, you can't actually download any of the files to your iPhone, but it works great for viewing images, natively supported movie files, PDFs, Office documents, and text files on the go.
The real reason this would excite most people is the possibility of accessing music files to get around the limitation of the iPhone's 4 and 8 GB capacity. Unfortunately, in its current state, music files aren't working yet--despite the fact that the iPhone is perfectly capable of playing them. According to the folks at Box, it's the way it's been coded on their end, and a fix is in the works.
A feature I'd like to see that simply isn't possible is to upload several iPhone-captured images to your box.net account in bulk. The good news is that you can get around this by e-mailing the files as attachments to your box.net account via the iPhone's mail application.
Here's a short clip of the new interface, opening up image, text, and PDF files over a Wi-Fi connection.