If you just have one login script doing not that much then just one script will do in most cases. We have almost no functionality in our logon script besides the calling of extra scripts to do the wanted/needed tasks. This way the number of scripts can become fairly large. With some kind of sorting mechanism by task the script does, by alphabet or like you said by OU, whatever it would be easier to locate the one script you need if you must/want to update the script.
_________________________
Mart

- Chuck Norris once sold ebay to ebay on ebay.