An interesting new product Autodesk would like you to test is called BIM Coordinator, it allows for an easy workflow of sharing coordinates between Civil 3D and Revit. It is currently available at Autodesk Labs.
An introduction for those not familiar Labs:
Autodesk labs is the traditional testing grounds for new technologies from Autodesk. The technologies regularly become new products or are incorporated into existing products as new features.
Link to software: http://labs.autodesk.com/utilities/bim_coordinator/
A video overview of the technology produced by Autodesk can be found here: http://www.youtube.com/watch?v=aSxbv7QPero
So, if you work on projects where data needs to be shared between Civil 3D and Revit, this technology is definitely worth a look!