I love app-iness in a cloud, and when it comes to business and "off time" there is an app for everyone.
Google Apps and Google Docs comes to the top of the list. If you are tired of having to constantly upgrade your office software products to do tasks like word processing, spread sheets and other business related programs then consider Google Apps which includes great features for group sharing, editing and more. It's one way for a business to reduce its operating costs.
Are you creative and love to work with images and more? Then head over to aviary.com and see all the great graphic tools which are available. Here I have a photo ready for needlepoint thanks to using filters and aviary software on their cloud.
Another favorite for photo storage and more is flickr.com which has great storage, editing tools, groups and more.
Talk to friends and associates using your video camera, & audio/speaker with SKYPE. Recently Skype added a feature for group conversation. The basic is free, and you can add phone and groups for minimal fee. Note that if you use Gmail, there is a video conference app there as well for no charge.
Keeping this short, so you can go ahead and test them out. Let's revisit this topic and I would love to hear what your favor free app in the clouds are!