Dropbox, one of my favorite cloud file storage/sync/share services, has an update that makes it very simple to share files and folders with others. In the past, the person you wanted to share with would need a Dropbox account for you to share files or folders. Now, you can share read-only folders with anyone using a link without needing to have a Dropbox account.
This is a nice feature, especially for teachers who may want to share a file or folder with students without the students needing a Dropbox account. If you need people to edit files, you'll want to share a folder with them (they need a Dropbox account), not a link, as links are read-only.
desktop
mobile
If you don't have a file sync/share/backup service yet, you should really look into getting one. It makes it easy to access your files anywhere, including on mobile devices, and saves you when a device crashes.
Source: Dropbox Blog
Related:
Dropbox - file sync, share, backup services. Free accounts available.
World Backup Day - make sure your data and files are backed up! - lots of great, free, file sync/share/backup services.