I don't know if you have access to a tape recorder but when my brother was in the hospice I would just talk into the tape, fill him in on what was going on, or tell silly jokes.

Sometimes if people were visiting, I just turned it on and let it record. Some of those were hysterical.

If he is going for outpatient chemo then you could find out what music he likes and send along some CD's. Sitting there getting chemo can take a while and headphones and a CD player help.