In reply to Magnus Berget:
I was there a few years ago, I would say you would be fairly to very limited without a car. The sergeant has lots to do, but there are lots of great crags up and down the valley that would hard to access. It's a fairly quiet valley, you might get lucky with lifts from other climbers or locals, but I wouldn't plan your trip around that.
Also there aren't really any shops, so unless you plan on bringing all your supplies up by public transport it could be tricky.
All that said, orco is an amazing place and has some fantastic climbing, enjoy!