In reply to veteye:
A very popular walk, if you are talking about where I think you are, is to go up the Brevent cable car and then for a long but flatish walk finally finishing descending to the Col des Montets. This is easy walking but offers great views of the Mont Blanc range because it is the other side of the valley. Equally if you catch the first stage of the Midi cablecar up to the Plan des Aiguilles there is great scope for long walks along paths directly under the Aiguilles.
If you want to be a bit more mountainous, and stay in huts, what about going up to the Albert Premier one night (not my favorite hut by a long chalk, but does have a pretty spectacular view for those not used to the high mountains), then cross the col to Trient hut for another night, on the Trient plateau. For this, obviously you would need to make sure he can tie on and is familiar with glacier precautions, but it should be worth it.