In reply to ROSP:
I agree, the campsite in Argentiere is fantastic. I stayed there a couple of weeks in early June last year. Didn't do much climbing thanks to 14 days or almost constant rain, but there definitely could have been worse places to spend time. A few of us were cooking under a covered communal area one night, and somehow after du vin we got onto dry tooling along the wooden support beam for the tarp 'roof'. A few minutes later the campsite man wandered over: 'don't do that...try the other beam, it's much more solid!'.
A very friendly place to spend some time.