To Mart thanks for your coding, but as you probably realised, I was not looking to find out the OU that the computer belongs to, but rather to find out what computers exist in an OU!
Allen, I tried your coding. I had to modify it as it came up with errors. Once I got rid of all the errors, the script seemed to enumerate all the Organistional Units rather than the computers within, so I will go with the script that Arend and Shanep put together as this script does the job beautifully.
In case anyone wonders why I was having problems with the path, its because I was doing the OU nesting backwards ie I should have put OUA in OUB in OUC, not OUC, OUB, OUA if that makes sense.