I'm in the process of transitioning development on a project of mine from Visual Studio.Net to XCode under OSX. One thing that's confusing me: Does XCode have an equivalent feature to solutions in VS.Net (workspaces in VC6)? I can't find a way to group projects logically and make them dependent on one another, but I know there has to be a way somehow.

I believe that "Projects" in VS.NET are closer to "Targets" in Xcode, and Xcode Projects would be the equivalent to VS.NET "Solutions."

You can create aggregate targets in Xcode, and specify dependencies on other targets in the target inspector window (select the target and press Command-I).