A little utility for Mac OS X that adds a Open Workspace menu entry which when activated opens the selected workspace in a new Eclipse instance. In addition Eclipse instance icons get a badge with the workspace name. This can be set in Preferences > General > Workspace. If unspecified the last segment of the workspace path will be used.
Since the 2.0 version one can use the Advanced... menu item that allows you to specify launch options when opening a new workspace. Using this you can for example easily debug a new instance of the running IDE without creating a launch configuration.
Note that OS X 10.6 or newer is required as this feature relies on the open command's ability to pass on arguments. Eclipse IDE 3.7+ and Java 1.6 or better is also required.