This is not something a purist would be caught doing, but Microsoft online storage service has been available for iOS users. The latest release adds a couple of new features such as support for Retina displays on the latest iDevices.
The SkyDrive app v2.1 for iOS has introduced some features such as the option to upload multiple pictures and videos, sharing of these files via e-mail or web link. The SkyDrive app also lets the user open files uploaded to SkyDrive using other iOS apps. So, if you fancy additional-based cloud storage, head to the iTunes store for the latest version.