Through Facebook, I discovered this great video on one young man's experience as an altar server:
I definitely agree that the altar server can distract from the liturgy if he is not focused on his duty, and that priests should encourage the use of cassocks and surplices instead of albs. A large reason for my joining the Seminary was my experience as an altar server, assisting some very humble priests who were great representatives of the Church and very close to Jesus—and this was reinforced by how reverent and dedicated they were to the celebration of Holy Mass.