Along with HTC's announcement of their One series devices, one thing that may have been overlooked while mulling the specs over was their new agreement with Dropbox. Previously, HTC was working with Dropbox to offer folks a free 5GB when using HTC devices but they've now bumped that up to 25GB free for 2-years:

Dropbox integrated with HTC Sense - HTC One gives you an easy way to save and share your photos and videos. HTC has integrated Dropbox into HTC Sense 4 enabling HTC One customers to get 25 gigabytes of free Dropbox space for two years. That’s enough to keep more than 10,000 high-quality photos. Dropbox is also integrated throughout HTC Sense 4, so it’s easy to edit, save and share your documents and other kinds of files.

We've gone through the process of explaining cloud storage services like Dropbox can be used for storing files, and now with it built-into Sense 4.0, it'll make things easier then ever.