myOSity.com reminds me of the original Microsoft Windows 3 Program Manager—an icon based launching pad to windowed applications (several of which are from various authors from around the web). Interestingly, according the the creator’s blog the project will be going open source onto CodePlex.
And for a very clever twist, check out Wiki-OS. The concept is to bring wiki-like editing to applications. The overall program (or perhaps I should call it a WebOS) is exceptionally well done. The company behind Wiki-OS is Userware.