Buying the vast feature set of a collaboration server like Microsoft Office Sharepoint would be overkill for many businesses. That's why Sharepoint has lots of competition from Web-based services that offer more-focused subsets of collaboration tools for fewer dollars, and in some cases for free. We looked at four alternatives to Microsoft's monolithic server: Central Desktop, Ninian Solutions' Huddle, 37Signals' Basecamp, and WebEx's WebOffice. Read more.