Tim in Belgium

Has anyone got any tips for what to do with soft luggage if you are on a touring trip and stop somewhere to visit somewhere/go shopping etc?

I have some soft Oxford panniers, and will be going off for a trip to Luxembourg, Germany and France in a weeks time, and will no doubt want to visit the odd chateau/shop/cave/museum etc. Don't fancy lugging all my gear around with me every where I stop.

Thanks,

Tim