Napkin, the new visual communication utility for Mac, can upload and share files over a number of services—one of them is iCloud.
[gallery link="file" columns="4" ids="3638,3637,3640,3636"]
Once you've added images and any annotations to your Napkin document, iCloud is the top option in the Share menu. When you use it, your file is uploaded and you get a short nap.kn URL with which to share it as an image on a webpage. But at the bottom of that page is a 'View on iCloud' option, which takes you to an iCloud.com/documents/ address and automatically downloads the shared image.
What I'm less clear on is how this iCloud integration works. I assume it uses the iCloud account of the currently logged in user, which means these files must count against our storage limit. The Napkin page has a notice at the top that files will "expire" in 14 days—does that mean they'll be deleted? Do we have any way to actually manage these files or see which ones we've shared?
Regardless, this is a clever feature that puts your iCloud account to good, convenient use for quick file sharing.
You can get Napkin in the Map App Store.