This script can take an ImmutableID found in the DirSync Metaverse or via get-msoluser and output the GUID of the corresponding object from the SOURCE AD.

It can also take the Source AD GUID and tell you what the ImmutableID should be.

   

Useful in troubleshooting DirSync issues and determining which AD Object maps to which MSOD object.

Examples:
To convert a GUID to an Immutable ID: GUID2ImmutableID.ps1 '748b2d72-706b-42f8-8b25-82fd8733860f'
To convert an ImmutableID to a GUID: GUID2ImmutableID.ps1 'ci2LdGtw+EKLJYL9hzOGDw=='

It can be found at: http://gallery.technet.microsoft.com/office/Covert-DirSyncMS-Online-5f3563b1