Multiple Solutions and Flat Projects

Graham Barry, one of the key VSTS members helping us pave our paths through Team Foundation Server, shared a model he likes to use.  He uses multiple solutions, but with a flat project list:

 /Source
   /WinFormsProject
    /WebProject
 /WindowsServiceProject
  /ClassLibrary1
  /ClassLibrary2
  /ClassLibrary3
  Web.sln
 Service.sln
 All.sln

It's flat, but effective.  You get flexibility and you avoid baking in a folder structure than can be tough to change.  You can also spin up solution files for presenting different working groups of the projects as you need them.