Built around , SkyDrive, and Hotmail (no, you don't have to actually use Hotmail), this simple collaboration setup gives you a single hub for shared documents and calendars, and bundles in the flexibility of group messaging if you use Microsoft Live Messenger.

Live Groups straddles the fuzzy gray line between the business cloud and the personal cloud, but it works effectively for both. It's by no means a full-fledged project management system. This can be a good thing when you just need to get down to sharing ideas and assets and don't want to burden your team with the hassle of bureaucratic tracking features.

For calendars and documents, Live Groups has a few distinct advantages over . The first is that it creates a stand-alone page that aggregates all of the stuff your team creates around the shared project. Office documents, calendar updates, and photos appear in the left column, with the most recent changes at the top, where everyone can get to them quickly. Events and actions, such as someone updating a Word document or modifying a meeting agenda, appear in the center column, so you can see at a glance what other members of the group have done lately.

Live Groups lets you assign more than one co-owner to a group, for easier administration. By default, however, new members have only basic permissions to add and edit documents, and can't invite new users to the group or change the group's settings.

For me, the most compelling thing about Groups is that it lets you edit documents either directly in the web interface or in 2003 and later on Windows or Office 2008 or later on the Mac. So if you're tired of sharing documents in Google Docs' clumsily simplistic interface and want to retain the formatting of your Word or Excel documents, you can stick the more robust tools you trust. And we might as well face it: Everyone's using Microsoft Office anyway.