I stuff them in the back of the car, nicads, nimhs, lipos, they're all the same.
You will only believe this is stupid IF you believe all the stupid scare stories, simple fact of the matter is I've been modelling for 13 years, and have only ever have one pack vent on me, and have never had one fail while in use.
I know someone who used to work for Al's Models, he was telling me about how they were throwing li-po's around, over charging and discharging them, and they were all fine.
All you have to do is make sure you look after the batteries properly, and don't short them etc, and they will be fine.
I have one of these hemp bag things, I put the packs in facing alternate ways, and go off to the races.
If you wanted something more substancial, a small toolbox from B&Q will suffice, or a quality street tin with a plastic bag or paper lining