WotC has a thread called "1001 Things Found In A Barrel" located here:
LinkThey are asking for people to post their ideas of what kinds of things you could find in a barrel in a D&D adventure.
Once they get enough entries one of the WotC people will create a downloadable random barrel contents generator. I figure once that is done it will be a simple matter to convert it into NWNScript then I'll post it for anyone to download for import into their own mod.
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