I've personally experienced 4 student workers at this point in my academic library career. There are several more who have worked when I work, but if they are stationed downstairs, I don't get to know them as well.
It's kind of rough for the students, because they are stuck in a fairly quiet--as in less frequented--part of the library (serials), often without any particular assignment except to be present at the desk. I think this led to some students being unreliable in showing up to work on a regular basis, which created trouble for them both in terms of how much they were paid and in being re-hired.
We have more work assignments for our evening students this semester, but not enough to fill a four hour shift. Over the past week, I had a student filling out book order cards, which is tedious, but still doesn't last very long (I think she spent 3-4 hours total to go through a whole review journals worth of orders). I think if we had a more standardized, comprehensive training program for students, we could assign more work to them (which would be great considering how short staffed we are!). As it is, we train them as we have assignments for them, but it seems that finding work for the students almost creates more work.
Ideas for student worker projects? Did any of you spend work-study or just plain student employment time at a library desk?