This script lists the contents of a specific datastore on ESX(i) and all subsequent folders providing the fileName, owner, fileSize and the type of file. In the current form, the script is to be executed against a specific ESX(i) host, but can be extended to query against a vCenter host, I will leave that as an additional exercise for end users.

Requirements:
ESX(i) 3.5 or 4.0
vSphere SDK for Perl or vMA 4.0

Sample Execution:

[vi-admin@scofield ~]$ ./listDatastoreFiles.pl --server esxi40-1.primp-industries.com --username root --datastore esxi40-1-local-storage
Enter password:

Name                                    Owner                                   Size                    Type
vm-1                                     | root                              | 1.50 KB              | FolderFileInfo
vm-2                                     | root                              | 980 Bytes            | FolderFileInfo
vm-1.vmx                                 | root                              | 2.63 KB              | VmConfigFileInfo
vm-1.vmdk                                | root                              | 0                    | VmDiskFileInfo
vm-1.nvram                               | root                              | 8.48 KB              | VmNvramFileInfo
vmware-1.log                             | root                              | 31.62 KB             | VmLogFileInfo
vmware.log                               | root                              | 30.81 KB             | VmLogFileInfo
vm-1.vmxf                                | root                              | 259 Bytes            | FileInfo
vm-1.vmsd                                | root                              | 0                    | FileInfo
vm-1-13e373e7.vswp                       | root                              | 1.00 GB              | FileInfo
vm-2.vmx                                 | root                              | 1.73 KB              | VmConfigFileInfo
vm-2.vmdk                                | root                              | 0                    | VmDiskFileInfo
vm-2.vmxf                                | root                              | 259 Bytes            | FileInfo
vm-2.vmsd                                | root                              | 0                    | FileInfo