From cloud storage, to color scheme generation, below is a list of online software services designed to aid and supplement various aspects of digital media. While none of them will be able to completely replace the desktop publishing applications we use on a day to day basis, you may find many of them extremely useful in easing certain processes!
A cloud storage service, Dropbox features a free, 2GB service with amazing syncing capabilities between computers, the web interface, and even mobile devices.
The web interface to Adobe's color scheme creator and management service. Tons of features, integrates with Photoshop, and totally free.