I found this in a few different places around the 'net - hopefully it's helpful:

Finding Encrypted Files

Unless you use a command-line utility like Cipher.exe, it's difficult to see at a glance which files are encrypted and which are not. Right-clicking each file and then choosing Properties, General, Advanced (followed by Cancel, Cancel) is tedious.

• Open a folder containing the encrypted files.
• On the View menu, choose Details, and then select Attributes. Encrypted files show a letter E in the Attributes column. You can also set an option so that the names of encrypted files appear in a different color from other file names.
  
• On the Tools menu, choose Folder Options, click the View tab, and select Show Encrypted Or Compressed NTFS Files In Color.