Not just yarn: knitting needles, notions, basic "how to knit" books/pamphlets/booklets, anything.
A woman in my local knit night at Loopy Yarns in Chicago is a counselor at a battered women's shelter, and thought that teaching the women how to knit would not only be therapeutic and confidence-building but also teaching them some skills that they can take with them.
So I thought I would send out the call to the most generous group of people I know. Would you be interested in something like this? I think that anything you have lying around would be sufficient.
PLMK if there's any interest in this and I will give you an address to send your stuff to.