Very cool tip from Ben Malone – he shows you how to use AdPointCloudIndexer.exe from a command line (outside of Revit) to prepare point clouds for practical use.  A typical 2013 location for this utility is:
C:Program FilesAutodeskRevit Architecture 2013ProgramAdPointCloudIndexer.exe

Image from BIMopedia

Read the whole post at:
Stand alone indexing of RAW point cloud data into .pcg files | BIMopedia

If you want to know more about different point cloud formats / file extensions, there is some info on the wiki:

  • Point Cloud Projects (*.rcp): Pick an indexed point cloud project file with .rcp extension. An .rcp is an aggregation of multiple .rcs point cloud files.
  • Point Clouds (*.rcs): Pick an indexed point cloud file with .rcs extension.
  • Raw formats: Pick a file with an extension in the list to automatically launch an indexer application that will convert the raw file to an indexed file.
    Note
    After the indexed file is created, you must use the Point Cloud tool again to insert the file.
  • All Files: Pick a file with any extension.

via
 Inserting a Point Cloud File – WikiHelp