An inexpensive, readily available gift that is good for both men and women is a challenge. Socks were a good idea. How about:
A mug
A bag of candy (has to be in a bag)
Items for a desk (pens, pencils, post-it notes, roll of tape, etc...give dimensions so that all items will fit within a small gift bag
Something in a can (might be able to get creative with that one)