I painted my bathroom walls on the weekend. Now that the paint is dry, I can see little hairs that were painted over on the wall. I washed the wall before I painted however, there must have been tiny hairs that were still stuck on the wall. I realize that I should have done a better job.

To fix the paint job, what do I need to do? Do I need to sand the wall down to nothing, or can I just buff out the rough spots and paint another layer? I used latex paint.

Sand out hairs and re-paint.

I agree but suggest you wait until the paint cures, sometimes over a week.