Not exactly a script, But

PACK MULE (the start of one anyways)

I made a merchant object, set the buy and sell to the minumum (all things bought for 1gp, all sold for 1gp) and no current inventory.

Took an OX and set him to the henchman settings (see making a henchman in one of the posts above)

In the conversation editor I set one line to activate his henchman status (nw_ch_join, I think, is the premade generic join as a henchman script, I know its one of the ones with 'join' at the end in any event), and another line as the 'start a merchant' script using my empty, no cost merchant object as the merchant.

This gives you an ox that follows you about and when you click on him opens an inventory you can move stuff too. It costs a gold for each transaction but the in/out makes that a wash.

I'll leave it to better men than I to deal with things like getting the merchant object to respawn into a new area with all the inventory intact, making the stuff appear in a pile of the ox gets killed, and such like, but even as is, anyone can make one just using the generic scrips already provided.

-M.